At least 45 Nigerian security personnel are dead after gunmen believed to be Boko Haram militants attacked the town of Buni Yadi.
Hundreds of gunmen on trucks and motorcycles stormed the town in northeastern Yobe state late Monday.
A source with Nigeria's Joint Task Force tells VOA's Hausa Service that 24 soldiers and 21 police officers were confirmed dead following the attack.
The source, who spoke on condition of anonymity, said the gunmen took away an armored tank and many vehicles.
There has been no word on civilian casualties.
A Hausa Service reporter who is in northeastern Nigeria said militants are also attacking motorists on highways leading in and out of Maiduguri, a city in Borno state.
Boko Haram is based in Borno state.
Drivers said snipers wait in trees to fire at passing cars, which are then attacked by gunmen hiding in bushes by the side of the road.
Despite promises of action from President Goodluck Jonathan, Nigerian security forces have been unable to stop the increasingly frequent attacks either claimed by or blamed on Boko Haram.
The twin bombings in the city of Jos last week killed 130 people, and Boko Haram continues to hold more than 200 schoolgirls kidnapped from a school in the village of Chibok last month.
The Islamist radicals have killed thousands of people over the past five years in attacks on schools, churches, mosques, bus stations and other public places.
On Monday, the head of the Nigerian military, Chief of Defense Staff Air Marshal Alex Badeh, said the military knew the location of the abducted Chibok schoolgirls.
VOA spoke by phone with family members of the missing girls about what Badeh called "good news" that the girls had been located.
Those relatives said their hopes have been raised before, but that they will believe the news when the girls are returned home safely.
The U.S. State Department says it has no independent information on the Nigerian government's claim that it knows the location of the schoolgirls kidnapped by Boko Haram extremists.
Spokeswoman Jen Psaki said Tuesday even if the United States knew where they are, it would not talk about it publicly.
She also said like the Nigerians, the U.S. would probably not attempt a rescue mission because of the safety and security of the girls.
Nigeria has accepted assistance from the United States and several other countries to help find the girls but has ruled out the use of foreign troops.
VOA's Anne Look in Abuja contributed to this report.