Thirty-five people have been killed after gunmen struck Niger's largest airport on Thursday, officials say - the second attack in less than five months. 

Residents in the predominately Muslim country told the BBC they had just finished their morning prayers when explosions and gunshot sounds rang out from Diori Hamani international airport, located in the capital, Niamey.

Niger's defence ministry said the fatalities comprised 22 assailants, 11 soldiers, and two civilians.

On Thursday evening, Al-Qaeda affiliate Jama'at Nusrat al-Islam wal-Muslimin (JNIM)claimed responsibility for the attack.

Niger has been fighting an Islamist insurgency for a decade and in January, an organisation linked to the Islamic State group claimed responsibility for an attack on the same airport.

Thursday's violence settled by mid-morning and security forces have since launched a manhunt for any remaining attackers.

Lawalli Tsalha, who lives near the airport, which also hosts a military base, told the BBC: "We finished our prayer at about 05:50 (04:50 GMT) and shortly afterwards we heard a loud bang - like something had exploded, perhaps a tyre.

"It was only a little later that we realised what was happening."

Authorities said alongside the 22 attackers that were killed, another four were wounded. They added that 20 suspects had been arrested. 

A large cache of weapons including RPG-7 launchers, AK-47 rifles, explosives, grenades, communications equipment and thousands of rounds of ammunition were also reportedly seized. 

Armed local residents joined the manhunt, though witnesses told the BBC that security personnel attempted to stop civilians getting involved.

One resident, who did not wish to be named, said: "The attackers mixed in with the local population, so finding them was not easy. Civilians picked up machetes and sticks to defend themselves and to strike anyone they did not recognise who came their way."

The airport vicinity had been locked down on Thursday afternoon, with security forces searching vehicles entering and leaving the area. 

African Union Commission Chairperson Mahmoud Ali Youssouf "strongly condemned" the assault and praised Nigerien forces whose actions "made it possible to repel the attack and secure the airport facilities."

Diori Hamani international airport is one of Niger's most sensitive security installations, serving as both a civilian aviation hub and a military base. 

It also hosts facilities linked to the Alliance of Sahel States (AES), which comprises Niger and its neighbours, Mali and Burkina Faso.

All three countries are run by juntas which came to power in part because of a failure to deal with years of jihadist violence in the region. 

In January's attack on the airport, four military personnel were injured and 20 attackers were killed, Niger's defence ministry said.

At the time, the head of Niger's military government, which has been in power for three years, thanked Russia for its help in foiling the attack. Abdourahamane Tiani also accused the presidents of France, Benin and Ivory Coast of backing those responsible.

He did not give details of what help Russia had provided, or provide any evidence to support his accusations against the other countries.

In recent weeks, authorities in Niger have demolished neighbourhoods near the airport, citing "terrorist risks". 

They have also extended the airport's perimeter fence and installed more than 350 surveillance cameras, AFP reports.