A roadside bomb hit a military patrol vehicle Sunday in the troubled northeastern Nigerian city of Maiduguri where attacks by suspected Islamists have killed dozens, residents said.

The blast occurred at around 6:00 pm (1700 GMT) in the Zinnari area of the city, which has been routinely targeted by the radical Boko Haram sect, they said.

"The military patrol van was passing along the street when it drove over a bomb which exploded with a thunderous blast and badly damaged the vehicle," Maiduguri trader Salisu Abubakar told AFP.

He said the blast was followed by gunshots from the attackers, causing panic as people ran for cover.

Abubakar could not say if anyone was hurt following the explosion.

Another resident, Babagana Dan-damasak said the vehicle "was mangled" from the explosion.

"It was evident that the bomb was planted on its path. Soldiers who came in trucks and vans surrounded the area and started a house-to-house search for the attackers," he added.

The military could not immediately confirm the incident.

Bomb and gun attacks blamed on Boko Haram, an extremist sect that sprung up in 2004, have been regular in some parts of the north, particularly Maiduguri in recent months.

In 2009, Boko Haram launched a short-lived armed uprising in a doomed bid to establish an Islamic state.

Although the rebellion was crushed in a military assault that killed hundreds, mostly sect members, it failed to deter further attacks.

In recent months the attacks have escalated.

The sect has claimed responsibility for the August 26 bomb blast at UN headquarters in Abuja that killed at least 24 people.