Nuclear-armed neighbours India and Pakistan agreed to a ceasefire on Saturday after U.S. pressure and four days of fighting, but within hours explosions rang out in border cities and towns and India accused Pakistan of violating the pact, Reuters reported.

Artillery fire and attack drones were witnessed in Jammu and Kashmir, the centre of much of the fighting, while blasts from air-defence systems boomed in cities under blackout, similar to the previous evening, according to authorities, residents and Reuters witnesses.

Indian Foreign Secretary Vikram Misri told reporters that Pakistan had violated the understanding arrived at by the two countries earlier in the day, and that the Indian armed forces had been instructed to “deal strongly” with any repetition.

“We call upon Pakistan to take appropriate steps to address these violations and deal with the situation with seriousness and responsibility,” Misri told a media briefing.

In response, the foreign ministry of Pakistan said the country was committed to the ceasefire and blamed India for the violations. “Our forces are handling the situation with responsibility and restraint,” it said.

The ministry also called on troops on the ground to exercise restraint and said that any issues in the implementation of the ceasefire should be addressed through communication at appropriate levels.

Pakistan’s military spokesperson did not immediately respond to requests for comment.

The fighting has been the worst between the old South Asian enemies in nearly three decades and threatened to erupt into a full-scale war in one of the world’s most volatile and densely populated regions.

There were briefly fears that nuclear arsenals might come into play as Pakistan’s military said a top body overseeing its nuclear weapons would meet.

But the defence minister said no such meeting was scheduled, hours after a night of heavy fighting in which the two countries targeted each other’s military bases and the combined civilian death toll rose to 66.

“Pakistan and India have agreed to a ceasefire with immediate effect,” Foreign Minister Ishaq Dar posted on X. “Pakistan has always strived for peace and security in the region, without compromising on its sovereignty and territorial integrity!”

Misri had earlier said the chiefs of the two countries’ military operations had spoken to each other and agreed that all fighting would stop at 5 p.m. Indian time (1130 GMT).

U.S. President Donald Trump posted: “After a long night of talks mediated by the United States, I am pleased to announce that India and Pakistan have agreed to a FULL AND IMMEDIATE CEASEFIRE. Congratulations to both Countries on using Common Sense and Great Intelligence.”

Dar told the broadcaster Geo News that military channels and hotlines between India and Pakistan had been activated, and three dozen countries had helped to facilitate the agreement.

On Wednesday, India had attacked what it said was “terrorist infrastructure” in Pakistani Kashmir and Pakistan, two weeks after 26 people were killed in an attack on Hindu tourists in Indian Kashmir, read the report.

Pakistan denied India’s accusations that it was involved in the attack. Days of cross-border fire, shelling and drone and missile attacks followed.

Despite the truce, two Indian government sources told Reuters that the punitive measures announced by India and reciprocated by Pakistan, such as trade suspension and visa cancellations, would remain in place for now.

The sources also said the 1960 Indus Waters Treaty, a critical water-sharing pact that India suspended after the Kashmir attack, would remain suspended.

The Indian foreign ministry did not respond to a request for comment.

U.S. Secretary of State Marco Rubio said that he and Vice President JD Vance had engaged with Indian Prime Minister Narendra Modi and Pakistan’s Shehbaz Sharif, Indian Foreign Minister Subrahmanyam Jaishankar, Pakistan’s army chief Asim Munir, and the two national security advisers over the course of 48 hours.

In a post on X, Rubio commended Modi and Sharif on the agreement, which he said included not only an immediate ceasefire but also the start of talks on “a broad set of issues at a neutral site.”

News of the ceasefire was greeted with relief on both sides of the border and Pakistan’s airport authority said its airspace had been fully reopened.

But the subsequent violations sparked alarm in India.

“What the hell just happened to the ceasefire? Explosions heard across Srinagar!!!”, Omar Abdullah, chief minister of Indian Kashmir, posted on X. “This is no ceasefire. The air defence units in the middle of Srinagar just opened up.”

India and Pakistan have been locked in a dispute over Kashmir ever since they were born at the end of British colonial rule in 1947. Hindu-majority India and Muslim Pakistan both rule part of Kashmir but claim it in full.

They have gone to war three times, including twice over Kashmir, alongside numerous smaller outbreaks of fighting.

India blames Pakistan for an insurgency in its part of Kashmir that began in 1989 and has killed tens of thousands. It also blames Pakistani Islamist militant groups for attacks elsewhere in India.

Pakistan rejects both charges. It says it provides only moral, political and diplomatic support to Kashmiri separatists, Reuters reported.

Pakistan said it launched a military operation against India early on Saturday, targeting multiple bases including a missile storage site in northern India as the neighbours extended their worst fighting in nearly three decades.

Pakistan said that before its offensive India had fired missiles at three air bases, including one close to the capital, Islamabad, but Pakistani air defences intercepted most of them, Reuters reported.

Locked in a longstanding dispute over Kashmir, the two countries have engaged in daily clashes since Wednesday when India launched strikes inside Pakistan on what it called “terrorist infrastructure”. Pakistan vowed to retaliate.

“BrahMos storage site has been taken out in general area Beas,” Pakistan’s military said in a message to journalists, adding that the Pathankot airfield in India’s western Punjab state and Udhampur Air Force Station in Indian Kashmir were also hit.

India’s defence and foreign ministries did not immediately respond to a request for comment outside regular business hours. India’s military was expected to brief the media shortly, the ministry of defence said in an advisory to the media.

Pakistan’s information minister said in a post on social media site X that the military operation was named “Operation Bunyanun Marsoos”. The term is taken from the Koran and means a firm, united structure.

Pakistan’s planning minister said on local television that “special measures” had been taken to avoid civilian targets and that they were targeting locations that had been used to target Pakistan.

Pakistan’s military said the prime minister had called a meeting of the National Command Authority, a top body of civilian and military officials, which oversees decisions on its nuclear arsenal.

Sounds of explosions were reported in India’s Srinagar and Jammu, where sirens were sounded, a Reuters witness said.

“India through its planes launched air-to-surface missiles … Nur Khan base, Mureed base and Shorkot base were made targets,” Pakistan military spokesman Lieutenant General Ahmed Sharif Chaudhry said in a late-night televised statement.

The chief minister of Indian Kashmir Omar Abdullah said in a statement a local administration official had been killed by shelling in Rajouri, near the line of control that divides the contested region.

One of the three air bases that Pakistan said were targeted by India is in the garrison city of Rawalpindi, just outside the capital Islamabad. The other two are in Pakistan’s eastern province of Punjab, which borders India.

The Pakistani military spokesman said only a few missiles made it past air defences, and those did not hit any “air assets”, according to initial damage assessments.

India has said its strikes on Wednesday, which started the clashes between the countries, were in retaliation for a deadly attack on Hindu tourists in Indian Kashmir last month.

Pakistan denied India’s accusations that it was involved in the tourist attack. Since Wednesday, the two countries have exchanged cross-border fire and shelling, and sent drones and missiles into each other’s airspace.

Much of the fighting on Friday was in Indian Kashmir and states bordering Pakistan. India said it shot down Pakistani drones.

The Group of Seven countries on Friday urged maximum restraint from both India and Pakistan and called on them to engage in direct dialogue. The United Kingdom’s High Commissioner to Pakistan, Jane Marriott, said in a statement on social media platform X that they were monitoring the developments closely.

Sounds of explosions were also heard in the eastern Pakistani city of Lahore and the northwestern city of Peshawar, as the fighting threatened to spread.

At least 48 people have been killed since Wednesday, according to casualty estimates on both sides of the border that have not been independently verified.

Blasts rang out across the Indian city of Jammu late on Thursday during what the government said was a Pakistani drone and missile attack on military stations around the Kashmir region on the second day of clashes between the nuclear-armed neighbours.

Sirens sounded and red flashes and projectiles erupted in the night sky above Jammu for about 2-1/2 hours, a Reuters journalist said, in what appeared to be an escalation in the countries’ worst confrontation in more than two decades, Reuters reported.

Two days of fighting have killed nearly four dozen people.

“Military stations at Jammu, Pathankot & Udhampur were targeted by Pakistani-origin drones and missiles along the international border in J&K today,” India’s Ministry of Defence said on X, citing places in and near the federal territory of Jammu and Kashmir.

“The threats were swiftly neutralised …. No casualties or material losses were reported.”

Indian TV channels also showed flares and flashes in the sky above Jaisalmer city in Rajasthan state, which shares a border with the southern Pakistani province of Sindh.

In a statement, Islamabad denied attacking Pathankot in India’s Punjab state, Srinagar in the Kashmir Valley and Jaisalmer and said the accusations were “entirely unfounded, politically motivated, and part of a reckless propaganda campaign aimed at maligning Pakistan”.

Pakistan’s Ministry of Foreign Affairs said the country would respond to any escalation “with full resolve and determination to safeguard Pakistan’s sovereignty and territorial integrity.”

Electricity in Jammu was slowly being restored after a blackout during the attack, a Reuters journalist said.

Eight missiles, fired from Pakistan at the Jammu region towns of Satwari, Samba, Ranbir Singh Pura and Arnia, were intercepted by air defence units, added an Indian military source who asked not to be named.

They were part of a wider attack, the source added.

Pakistan’s Defence Minister Khawaja Muhammad Asif earlier said further retaliation was “increasingly certain” after both countries accused each other of launching drone attacks.

World powers from the U.S. to Russia and China have called for calm in one of the world’s most dangerous and populated nuclear flashpoint regions. The U.S. Consulate General in Pakistan’s Lahore ordered staff to shelter in place.

U.S. Secretary of State Marco Rubio called for de-escalation in separate calls with Indian Foreign Minister Subrahmanyam Jaishankar and Pakistani Prime Minister Shehbaz Sharif on Thursday, the State Department said.

The relationship between India and Pakistan has been fraught with tension since they gained independence from colonial Britain in 1947. The countries have fought three wars, two of them over Kashmir, and clashed many times.

The neighbours, which both claim Kashmir in full and rule over parts of it, separately acquired nuclear weapons in the 1990s.

DRONES, MISSILES, AIR DEFENCES

In the latest confrontations, India said it hit nine “terrorist infrastructure” sites in Pakistan on Wednesday in retaliation for what it says was a deadly Islamabad-backed attack in Indian Kashmir on April 22.

Pakistan says it was not involved and denied that any of the sites hit by India were militant bases. It said it shot down five Indian aircraft on Wednesday, a report the Indian embassy in Beijing dismissed as “misinformation”.

Pakistan’s military said earlier on Thursday it shot down 29 drones from India at multiple locations including the two largest cities of Karachi and Lahore and the garrison city of Rawalpindi, home to the army’s headquarters.

The Indian defence ministry said Pakistan attempted to engage a number of military targets in northern and western India from Wednesday night into Thursday morning and they were “neutralised” by Indian air defence systems.

In response, Indian forces targeted air defence radars and systems at a number of locations in Pakistan on Thursday, the ministry said.

Before trading ended, both countries saw their stocks, bonds and currencies decline, and Pakistan’s benchmark share index closed down 5.9%.

Local media reported panic buying in some cities in the Indian state of Punjab, which shares a border with Pakistan, as people hoarded essentials.