More than a dozen people, including seven soldiers, were killed by Islamist militants in an attack in northeast Nigeria, four sources told Reuters. The militants arrived in the Ajiri community in the Mafa local government area of Borno state on motorcycles early on Sunday, killing an army commanding officer and six soldiers, the sources said. The assailants also killed six civilians, burned down nine housing blocks and carted away valuables, the sources - one soldier, one civilian fighter and two local government officials - told Reuters. In a statement, the military said troops repelled the attack but that militants killed some residents and two military personnel. Attacks by Islamist militants have been intensifying in northeast Nigeria in recent months, with dozens of soldiers killed and thousands of Nigerians displaced. Army spokesman Mohammed Yerima said the military on Saturday repelled another attack on Rann, capital of the Kala Balge local government area of Borno. Two sources, one soldier and one local resident, said troops killed nine militants. Yerima said in the statement that the troops also captured weapons including an anti-aircraft gun barrel, an AK-47 rifle and different calibres of ammunition.