MAIDUGURI: Boko Haram Islamic extremists struck the northeast Nigerian city of Maiduguri for the first time in months Monday with rocket-propelled grenades and multiple suicide bombers, witnesses said.

At least 15 people were killed but the toll was feared many times higher.

Nigerian troops "intercepted and destroyed" 10 suicide bombers, according to PR Nigeria, an agency that disseminates government news.

Maiduguri, the city under attack, is the birthplace of Boko Haram, which emerged as a much more radical entity after Nigerian security forces attacked their compound there, killing 700 people in 2009.

Militants firing indiscriminately from the back of three trucks attacked the outlying village of Dawari, soldiers engaged them, and as people were fleeing, a woman ran into a suburb yelling "Boko Haram, Boko Haram."

When people gathered, she detonated herself, according to village head Bulama Isa.

As the chaos reigned and a rocket-propelled grenade exploded, setting alight grass-thatched huts, a second woman blew herself up, according to Isa.

The village chief, 10 of his children and others were killed in Duwari, an outlying suburb of Maiduguri, according to residents Ahmed Bala and Umar Ibrahim.

"The troops laid ambush on the terrorists' suspected routes. ...The suicide bombers were intercepted in three different locations approaching the city," PR Nigeria said, quoting the military.

The area is close to Giwa Barracks, a major military base attacked several times in the past by the extremists.

In January 2014, Boko Haram attacked the base and freed hundreds of detainees.

Nigeria's military is accused of killing thousands of detainees there, by human rights groups.

The attack comes as Nigeria's government says it has contained the Islamic uprising that has killed 20,000 people in six years and driven 2.3 million people from their homes.

The government claim is impossible to ascertain in an area where access is dangerous and restricted by the military.

But the report of the attack, a few dozen insurgents in three trucks, is a far cry from previous attacks by hundreds of militants including tanks stolen from the military.

It could bear out the government's report that most terrorist hideouts have been destroyed and they are reduced to seeking "soft targets" through suicide bombings.