At least 64 people were feared dead following a boat accident on a river in Zamfara State in northwest Nigeria, local officials said on Saturday.

A wooden boat carrying 70 farmers capsized as it was transporting them across the river to reach their farmlands close to Gummi town on Saturday morning. Local authorities swiftly mobilised residents for a rescue operation, and after three hours, six survivors were pulled from the water.

"This is the second time such an incident has occurred in the Gummi Local Government Area," said Aminu Nuhu Falale, a local administrator who led the rescue efforts.

He added that emergency teams were intensifying their search in the hope of finding more survivors.

More than 900 farmers rely on crossing the river daily to access their farmlands, but only two boats are available, often leading to overcrowding, said the local traditional ruler.

Zamfara State, already plagued by criminal gangs seeking control of mineral resources, has also been severely affected by flooding caused by heavy rains. Two weeks ago, floods displaced more than 10,000 residents, local officials said.

Comoros President Azali Assoumani was slightly injured in a knife attack on Friday, the archipelago nation's government spokesperson said, adding that the attacker has been taken into custody.

The incident occurred around 2 p.m. (1100 GMT) in Salimani Itsandra, a town just north of the capital Moroni, Reuters reported citing a local source.

"President Azali Assoumani was slightly injured with a knife during the funeral of a great sheikh of the country. His injuries are not serious and he has returned home," government spokesperson Fatima Ahamada told Reuters.

The motive for the attack was not immediately clear.

The source from the town of Salimani Itsandra added that the attacker is a former policeman in his 20s.

In May, Assoumani was sworn in for a fourth term in office following a tense January election which his opponents claim was tainted by voter fraud.

North Korea for the first time showed images of the centrifuges that produce fuel for its nuclear bombs on Friday, as leader Kim Jong Un visited a uranium enrichment facility and called for more weapons-grade material to boost the arsenal.

The state media report on Kim's visit to the Nuclear Weapons Institute and a production base for weapon-grade nuclear materials was accompanied by the first photos of the centrifuges, providing a rare look inside North Korea's nuclear programme, which is banned under multiple United Nations Security Council resolutions, Reuters reported.

The photos showed Kim walking between long rows of metal centrifuges, the machines that enrich uranium. The report did not make clear when the visit occurred nor the facility's location.

Kim urged workers to produce more materials for tactical nuclear weapons, saying the country's nuclear arsenal is vital for confronting threats from the United States and its allies.

The weapons are needed for "self-defence and the capability for a preemptive attack," he said.

The North Korean leader said "anti-DPRK nuclear threats" from the "U.S. imperialists-led vassal forces" have crossed the red-line, according to the report.

South Korea condemned North Korea's unveiling of its uranium enrichment facility and will never accept Pyongyang's possession of nuclear weapons, the South's unification ministry said.

North Korea is believed to have several sites for enriching uranium. Analysts say commercial satellite imagery has shown construction in recent years at the main Yongbyon Nuclear Scientific Research Center, including its uranium enrichment plant, suggesting possible expansion.

Uranium is a radioactive element that exists naturally. To make nuclear fuel, raw uranium undergoes processes that result in a material with an increased concentration of the isotope uranium-235.

International Atomic Energy Agency chief Rafael Grossi said on Monday that the U.N. nuclear watchdog had observed activity consistent with the operation of a reactor and the reported centrifuge enrichment facility at Yongbyon.

NEW CENTRIFUGES

Kim stressed the need to boost the number of centrifuges so as to "exponentially increase" North Korea's nuclear arsenal, and expand the use of a new type of centrifuge to strengthen the production of weapon-grade nuclear materials.

The centrifuges seen in the photos appear smaller and shorter than the types previously believed to be used by North Korea, suggesting it had developed its own centrifuges to enhance separation capabilities, said Lee Sang-kyu, a nuclear engineering expert at South Korea's Korea Institute for Defense Analysis.

The photos also confirmed that the North is using a cascade system where large numbers of centrifuges are interconnected to achieve highly enriched uranium, he added.

The new type of centrifuge shows North Korea is advancing its fuel cycle capabilities, said Ankit Panda of the U.S.-based Carnegie Endowment for International Peace.

"Kim also appears to suggest that North Korean tactical nuclear weapons designs may primarily rely on uranium for their cores," he said.

This is notable because North Korea is more able to scale up its highly enriched uranium stockpiles, Panda said, compared to the more complicated process for plutonium.

'INCREASING ARSENALS'

North Korea invited some foreign scientists to view a centrifuge facility at Yongbyon in 2010, but Jenny Town of the U.S.-based Stimson Center said Friday's report is the first and only photographs of the equipment.

"It shows how advanced their enrichment capability has become, which gives greater credibility to both their ability and commitment to increasing their nuclear weapons arsenals," she said.

It could also be meant to influence the U.S. election and send a message to the next administration that denuclearisation is no longer possible and it should recognise North Korea as a nuclear state, said Hong Min, a senior researcher at the Korea Institute for National Unification in Seoul.

North Korea has previously shown photos of what it says were nuclear warheads. It has conducted six underground nuclear tests between 2006 and 2017.

Estimates of the number of North Korean nuclear weapons varies widely. In July a report by the Federation of American Scientists concluded that the country may have produced enough fissile material to build up to 90 nuclear warheads, but that it has likely assembled closer to 50.

Kim also oversaw the test launch of a new 600mm multiple launch rocket system on Thursday and visited an army training base on Wednesday, according to separate KCNA reports.