NIAMEY (AFP) - Niger is set to send troops to Nigeria for the multi-national battle against Boko Haram after scores of people were killed in a fresh onslaught by the Islamist fighters in a key border town.

Intervention from Niger would open a new northern front in the increasingly regional fight against the Islamist insurgents who killed more than a hundred people, including 19 soldiers, on Wednesday in a rampage in the Cameroonian town of Fotokol on Nigeria's border.

The onslaught came a day after Chad sent troops across the frontier to battle the extremists and recapture the Nigerian town of Gamboru. Chad's army said it had killed more than 200 Boko Haram fighters in the clashes.

"They (Boko Haram) attacked and burnt three mosques in the attack," Mele Mohammed, a Fotokol community leader, told AFP. "In the mosque, in the Tashangalau area, they killed 31 people who were praying."

He added: "Our consolation is that our attackers also suffered heavy casualties, especially when the fighter jets bombed them as they fled."

A government source said Niger's parliament will vote Monday on sending its troops to Nigeria to fight the militants, who have killed 3,000 people and forced more than a million from their homes since launching its insurgency in 2009.

"Niger is indeed going to send troops to Nigeria as part of the struggle against Boko Haram," the source said.

Nothing more than a stream, the Komadougou Yobe marks the frontier between Niger and Nigeria, and the water level has recently dropped considerably, making it easy for troops to cross.

African Union leaders have backed plans for a 7,500-strong five-nation regional force to take on the extremists, who control vast swathes of northeast Nigeria.

The UN Security Council on Thursday urged Nigeria's neighbours to step up military cooperation, praising Chad's "swift assistance in the fight against Boko Haram".

African and Western experts met in Cameroon's capital Yaounde on Thursday to devise the combat strategy against the Islamist militants.

The three-day summit "amounts to a crucial, determining and decisive step in the war that the international community has decided to intensify against Boko Haram," Cameroon's Defence Minister Edgar Alain Mebe Ngo'o said.

Nigeria's military has drawn fierce criticism for failing to rein in the insurgents, who have stepped up their campaign of terror in the northeast in the run-up to presidential and parliamentary elections planned for February 14.

Viewing the widening field of Boko Haram activity a direct threat to its national interests, Chad has had troops equipped with tanks and hundreds of other vehicles stationed since Monday on Niger's territory in the Bosso region adjoining the border with Nigeria.

French President Francois Hollande on Thursday called on the international community to help fight extremism in Africa, instead of talking on the sidelines.

"Do your job, don't give lessons, act. Do your duty, no one else will do it in your place," Mr Hollande said.

France is supporting the operations by carrying out reconnaissance flights over border areas of Chad and Cameroon to provide the two nations with intelligence, defence officials in Paris have said.

Boko Haram has seized control of vast tracts of northeastern Nigeria, including the strategic town of Baga in the Lake Chad region where the borders of four countries converge.