The vast basin has become the epicentre of violence led by Nigeria's Boko Haram and its rival branch Islamic State West Africa Province (ISWAP).

"The aim of this special operation was to neutralise the ISWAP bases in the Matari forest (of Nigeria) from where every year attacks are led" on three towns with army outposts in Niger, the multinational force said.

The bombardment took place late last week after observing "about 50 terrorists" in the region on Friday and Saturday, a statement said.

Much of the operation was carried out by troops from Niger "with the support of a drone from American partners", it added.

Thirty-six suspected terrorists were captured and an encampment and base camp were "destroyed", the force said.

"A large number of these criminals on the run ... were intercepted."

The multinational force said it suffered no losses.

The three towns of Maine Soroa, Chetinari and Chetimari Wangou, located in the Diffa region of southeast Niger have suffered repeated jihadist attacks since 2015.

Maine Soroa, 70 kilometres (45 miles) from Diffa, had been spared until 2019 when a violent attack saw Doctors without Borders (MSF) pullout after suspected jihadists raided the NGO's offices there.

The military post at Chetimari Wangou, 25 kilometres from Diffa, has been attacked by ISWAP several times.

Last June, the multinational force announced it had killed more than 800 ISWAP fighters over two months in the vast marshy Lake Chad area, bordering the four nations.

Nigerian security forces are battling Boko Haram and ISWAP jihadists in the country's northeast, where the conflict has killed 40,000 people and displaced 2.2 million more

The four nations set up the 8,500-strong multinational force in 2105 to tackle the armed groups.

The states around Lake Chad and international donors last week pledged at a conference in Niamey more than $500 million to help the millions of civilians threatened by jihadist insurgents and climate change in the region.