Nigeria's military says Islamic extremists firing anti-aircraft rockets and rocket-propelled grenades attacked a tank battalion barracks in the northeast of the country, and witnesses say they set the entire complex ablaze.

Spokesman Maj. Gen. Chris Olukolade says the pre-dawn attack Friday in Bama was repelled by fighter jets and a ground assault.

The second major attack on security force installations this month raises doubts about the military's ability to halt the Islamic uprising despite a 7-month-old state of emergency in three northeastern states covering one-sixth of Africa's biggest oil producer.

Olukolade said the attackers came across the border from Cameroon, which Nigerian officials say is doing little to stop the extremists using the country as a launch pad for attacks and escape routes.

Thousands have died in the 4-year-old insurgency.