Chad's army killed more than 200 militants from Boko Haram on Tuesday in fighting in northeastern Nigeria, with nine of its own forces killed, the army and state television said on Wednesday.

Chad has deployed 2,500 troops as part of a regional effort to take on the militant group, which has been fighting for five years to create an Islamist emirate in northern Nigeria. An estimated 10,000 people died in the region last year.

Chad's army destroyed more than a dozen vehicles equipped with heavy weapons and some 100 motorcycles used by the militants in battles in the towns of Gambaru and Ngala, the army high command said in a statement on Wednesday.

There was no independent confirmation of its claim.

Militants also attacked the town of Fotokol in Cameroon on Wednesday in the latest cross-border incursion by the group, which operates near Nigeria's frontiers with Niger, Chad and Cameroon.

The fighters attacked at around 5 a.m. (0400 GMT) after Chadian troops who were temporarily based there crossed over to Gambaru on Tuesday, according to a Cameroonian military officer close to the operation and a Cameroon military source.

"The insurgents have been driven out. They tried to surprise us because the Chadian troops who were in Fotokol had crossed over to Nigeria," Cameroonian Information Minister Issa Tchiroma told Reuters by telephone.

The attack provoked intense fighting and six Cameroonian soldiers were killed, said the Cameroonian officer, who declined to be identified. He said that forces in the town had called for reinforcements and the fighting had now subsided.