Cameroon's foreign minister says a five-country African coalition will soon be operational to fight terrorism, notably Nigeria-based Boko Haram.

Pierre Moukoko Mbonjo says the force to include 3,500 soldiers from Benin, Chad, Cameroon, Niger and Nigeria will be operating within weeks.

Mbonjo said Nigeria neighbor Cameroon now faces repeat attacks by Boko Haram: "You should understand that we are at war; A war imposed on us and whose aims are still not clear."

The minister conveyed a message from Cameroon President Paul Biya that "the situation is under control," but "vigilance remains necessary."

Mbonjo spoke to The Associated Press late Sunday in Dakar where he was attending a summit of French-speaking countries.

Boko Haram seeks to impose Islamic Shariah law in Nigeria, Africa's most populous nation at about 170 million.