Britain and Egypt asked their airlines on Wednesday to avoid Iranian and Lebanese airspace amid growing fears of a possible broader conflict in the region after the killing of senior members of militant groups Hamas and Hezbollah, Reuters reported.

Britain’s advisory to its airlines to avoid Lebanon’s airspace came hours after Egypt instructed all of its airlines to avoid Iran’s airspace for three hours in the early morning on Thursday.

Many airlines globally are revising their schedules to avoid Iranian and Lebanese airspace while also calling off flights to Israel and Lebanon.

Flights through conflict zones became a prominent industry safety issue a decade ago after Malaysia Airlines flight MH17 was shot down over Ukraine, killing all 298 people on board.

U.S.-based United Airlines (UAL.O), opens new tab said on Wednesday its flights to Tel Aviv, which were paused on July 31 due to security concerns, remained suspended. “We continue to closely monitor the situation and will focus on the safety of our customers and crews as we decide when to resume service,” the airline said.

Its rival Delta Air Lines (DAL.N), opens new tab has paused its flights between New York and Tel Aviv through Aug. 31, read the report.

British carriers are not flying to Lebanon currently, according to flight tracking website Flightradar24.

Singapore Airlines (SIAL.SI), opens new tab stopped flying through Iranian airspace last Friday and is using alternative routes, saying safety is its top priority.

Similarly, Egyptian airlines have already been avoiding Iran’s airspace. The new directive applies to all Egyptian carriers, including charter operators and other smaller airlines, said Mark Zee, founder of OPSGROUP – a membership-based organization that shares flight-risk information.

Egypt’s NOTAM, a safety notice provided to pilots, said the instruction would be in effect from 0100 to 0400 GMT on Thursday.

“All Egyptian carriers shall avoid overflying Tehran (Flight Information Region). No flight plan will be accepted overflying such territory,” the notice said, referring to the three-hour period specified.

Egypt’s civil aviation ministry later confirmed on Wednesday the notice was intended to reduce flight safety risks in light of a notification it received from Iranian authorities, Reuters reported.

“Military exercises will be conducted over Iranian airspace on Aug. 7 from 11:30 to 14:30 and from 4:30 to 7:30 on Aug. 8 Tehran time,” the statement said.

The ministry’s press statement followed an unnamed source quoted by the state-affiliated Al Qahera News TV as saying that Iranian authorities had said to avoid flying in the country’s airspace because of “military exercises.”

Iran’s Acting Foreign Minister Ali Bagheri Kani spoke with the Egyptian foreign minister by phone on Wednesday, according to Iranian foreign ministry’s website.

In 2020, Iranian air defence units said they mistakenly shot down Ukrainian International Airlines flight PS752, killing all 176 people on board, shortly after it took off from Tehran airport. At the time, they were on heightened alert because of increased tensions with the United States.

On Sunday, Jordanian authorities asked all airlines landing at its airports to carry 45 minutes’ worth of extra fuel, Reuters reported.

Countries in the region, including Jordan, closed their airspace earlier this year amidst aerial attacks on Israel.

The United States has communicated to Iran and Israel that conflict in the Middle East must not escalate, Secretary of State Antony Blinken said on Tuesday, even as the Pentagon warned that it would not tolerate attacks against its forces in the region, Reuters reported.

The Middle East is bracing for a possible new wave of attacks by Iran and its allies following last week’s killing of senior members of militant groups Hamas and Hezbollah. Five U.S. troops and two contractors were injured in an attack on a base in Iraq on Monday, which U.S. Defense Secretary Lloyd Austin blamed on Iran-backed groups.

Officials had been in constant contact with allies and partners in the region and there was a “clear consensus” that no one should escalate the situation, the top U.S. diplomat said.

“We’ve been engaged in intense diplomacy with allies and partners, communicating that message directly to Iran. We’ve communicated that message directly to Israel,” Blinken said.

The United States will continue to defend Israel against attacks, Blinken said, but noted that everyone in the region should understand the risks of escalation and miscalculation, read the report.

“Further attacks only raise the risk of dangerous outcomes that no one can predict and no one can fully control.”

The Pentagon has said it will deploy additional fighter jets and Navy warships to the Middle East as Washington seeks to bolster defenses in the region.

“What I’ve been focused on is making sure that we’re doing everything we can to put measures in place to protect our troops and also make sure that we’re in a good position to aid in the in the defense of Israel, if called upon to do that,” Austin said.

Blinken, following a meeting involving Austin and their Australian counterparts, also said talks to achieve a ceasefire and hostage deal on the war in Gaza had reached their final stage and should end very soon.

Ismail Haniyeh, the political leader of Palestinian Islamist group Hamas, was assassinated in the Iranian capital of Tehran last week. The attack drew threats of revenge by Iran on Israel, which has not claimed responsibility, Reuters reported.

Coupled with the killing of the senior military commander of the Lebanese group Hezbollah, Fuad Shukr, by Israel in a strike on Beirut last week, concern has intensified that the conflict in Gaza is turning into a wider Middle East war.

Iran has said the U.S. bears responsibility in the assassination of Haniyeh because of its support for Israel.

On Monday, a rocket attack on al Asad airbase in western Iraq injured seven U.S. personnel.

Austin said the United States “will not tolerate” attacks on its personnel.

Asked if he knew who was behind the attack, Austin added the U.S. was sure it was an Iran-backed militia, but had not determined which one.

“We’re still investigating to determine that,” he said.

Iraq’s military condemned on Tuesday what it called “reckless” actions against bases on its soil and said it had captured a truck with a rocket launcher.

A small truck was seized with a rocket launcher fixed on the back. Eight unfired rockets were dismantled, the statement said.

A rare ally of both the U.S. and Iran, Iraq hosts 2,500 U.S. troops and has Iran-backed militias linked to its security forces. It has witnessed escalating tit-for-tat attacks since the Israel-Hamas war erupted in October, Reuters reported.

An Israeli airstrike hit two schools in Gaza City on Sunday, killing at least 30 people, Palestinian officials said, while the Israeli military said it struck a Hamas military compound embedded in the schools.

An Israeli airstrike hit a tent camp inside a hospital in central Gaza earlier in the day. Gaza health officials said a total of at least 44 Palestinians were killed on Sunday, the day after a round of talks in Cairo ended without result, Reuters reported.

Footage circulated on Palestinian media showed bodies scattered inside the yard of one of two blast-wrecked schools as residents rushed to carry casualties, including children, and loaded them into ambulance vehicles that took them to at least two nearby hospitals.

Gaza’s Civil Emergency Service said dozens were wounded in addition to the fatalities in the schools of Hassan Salama and Al-Nasser, which housed Palestinian displaced families.

The Israeli military said it struck militants inside a Hamas command embedded within the schools and that it took steps to reduce the risk to civilians there.

Israel says the Islamist militant group Hamas regularly embeds in civilian institutions, using Gaza’s population as human shields. Hamas denies this.

Earlier in the day, an Israeli strike inside the Al-Aqsa Hospital compound started a fire, and wounded at least 18 people as well as killing five, medical authorities said.

The Israeli military said it struck a militant operating there and that secondary explosions were identified, indicating weapons were present in the area.

Israel is bracing for a serious escalation following the assassination of Hamas’ leader Ismail Haniyeh in Tehran on Wednesday, a day after an Israeli strike in Beirut killed Fuad Shukr, a top military commander from Lebanese armed group Hezbollah.

Israeli Prime Minister Benjamin Netanyahu was due to convene special security discussions late on Sunday, a defence official said, following threats of retaliation from Iran and Hezbollah.

Defence Minister Yoav Gallant said he was reviewing plans “that would exact a price in the case of attempts by Iran and its proxies to attack Israel.”

“Our readiness in terms of defense is high – be it on the ground or in the air, and we are prepared for both a swift response or attack. If they dare to attack us, they will pay a heavy price,” Gallant said in a statement.

Hamas and Iran have both accused Israel of carrying out the assassination of Haniyeh and have pledged to retaliate. Israel has neither claimed nor denied responsibility for the death.

Hezbollah, like Hamas, is backed by Iran and has also vowed revenge after the killing of Shukr.