A teenage suicide bomber detonated an explosive device strapped to her body in the northeastern Nigerian city of Damaturu early today, killing five people and wounding about 30, police said.

No one claimed responsibility for the blast but Islamist militant group Boko Haram has been blamed for a series of similar attacks in the region in recent weeks.

"At about 7:40 a.m., a female suicide bomber about 14 years old denoted an explosive device at the central Damaturu motor park. Six people were killed including the suicide bomber," police spokesman Toyin Gbadegesin said.

An official at the state emergency management agency said the suicide bomber tried to enter the motor park, or bus station, and was accosted by civilian viligantes. She then pulled away and set off the bomb, Idi Musa Jigawa told Reuters.

Jigawa said six people were critically wounded and another 22 had minor injuries. He confirmed the death toll given by police.

"I was inside the park, just boarded a bus when I heard a loud noise. Some policemen came to the scene and evacuated corpses," an eyewitness travelling to Maiduguri told Reuters.

Boko Haram has waged a deadly campaign for the past six years to carve out a state adhering to strict Islamic law in northeast Nigeria. After being pushed out earlier this year from most of the territory it had gained, the group scattered and returned to attacking soft targets.

Gbadegesin said another child suicide bomber, age 12, set off an explosion at a security checkpoint after the motor park attack, but there were no casualties.