Niger, Chad, and Cameroon are seeking to undermine Boko Haram fighters in Nigeria ahead of a ground-and-air offensive by a regional taskforce due to start from the end of next month, a senior Niger military official said.

Military chiefs will meet in the Chadian capital N'Djamena next week to finalise strategy for the 8,700-strong taskforce of troops from the African coalition, said Colonel Mahamane Laminou Sani, director of documentation and military intelligence of Niger's armed forces.

"All we are doing right now is stopping Boko Haram from entering Niger: if they attack our positions we push them back a certain distance and Nigeria pushes from the other side to contain the situation," he said on Wednesday, on the sidelines of the annual US-sponsored 'Flintlock' counter-terrorism exercises in Chad.

"There are initiatives by our countries to make sure Boko Haram doesn't get out of control but we have a deadline of end-March to put the joint force into practice," he added.

Boko Haram, which has killed thousands of people in a six-year rebellion in Nigeria, has fought fierce battles with the three countries' armies in southern Niger and northern Cameroon, near Nigeria's borders, in recent weeks.

Heavy casualties

Chadian forces have made incursions into Nigeria to push back the fighters, hundreds of whom have been killed.

In the most recent development, Boko Haram suffered heavy casualties in battles with Chadian troops in Nigeria this week, residents who fled the fighting have said.

Chad's army said on Tuesday evening that they had seized contol of the town of Dikwa, which is about 50km southwest of the Nigerian border town of Gamoru.

"When they came into Dikwa there was intense fighting but at last they subdued the Boko Haram fighters," Bababura Diwa, a resident of the town, said.

"They killed many of them, including Abu Ashshe, their commander."

Furthermore, Nigeria's military said on Wednesday that it had killed more than 300 Boko Haram fighters during an operation to recapture 11 towns and villages since the start of the week.

Source: Agencies