Boko Haram fighters have shot or burned to death dozens of civilians in a border town near Nigeria, Cameroon's government spokesman said Thursday.

Some 800 Islamic extremists attacking the town of Fotokol have "burned churches, mosques and villages and slaughtered youth who resisted joining them to fight Cameroonian forces," said Information Minister Issa Tchiroma Bakari.

The insurgents also looted livestock and food in the fighting that began Wednesday and is continuing Thursday, Bakari told The Associated Press.

Boko Haram is using civilians as shields, making it difficult to confront them although reinforcements have arrived in Fotokol, according to military spokesman Col. Didier Badjeck.

The fighters are believed to have crossed into Cameroon from nearby Gamboru, a Nigerian border town from where they were driven out by Chadian and Nigerian air strikes and ground troops earlier this week.

The news comes as African Union officials are finalizing plans for a multinational force to fight the spreading Islamic uprising, although there are questions about funding. The African Union last week authorized a 7,500-strong force from Nigeria and its four neighbors, Cameroon, Chad, Niger and Benin.

Senior officers from the U.N. peacekeeping department are attending the meeting that started Thursday in Yaounde, Cameroon's capital, said a U.N. official.

The Africans want U.N. Security Council approval and money to fund the mission, said the official who spoke Wednesday at the United Nations and insisted on anonymity because he was not authorized to speak to the press on the meeting.

International concern has grown as Boko Haram has increased the tempo and ferocity of its attacks just as Nigeria is preparing for presidential and legislative elections on Feb. 14.

Some 10,000 people were killed in Boko Haram violence last year compared to 2,000 in the first four years of Nigeria's Islamic uprising, according to the Council on Foreign Relations.