A suicide bomber driving a tricycle, struck a crowded market in the northeastern Nigerian city of Maiduguri on Friday, killing six people, the national Emergency Management Agency (NEMA) said, in an attack that bore the hallmarks of Islamist militant group Boko Haram.

There was no immediate claim of responsibility for the blast, but Maiduguri, the capital of Borno state, has been often been targeted by Boko Haram in its campaign to carve out an Islamic “caliphate” in Nigeria’s northeast.

Eleven people were wounded in the attack, the latest in a spate of bombings and shootings that have killed more than 600 people across the north, according to a Reuters tally, since President Muhammadu Buhari was inaugurated on May 29.

Witnesses said the driver of a motorised rickshaw detonated a device at the entrance to the crowded market around 7.30 a.m. (0630 GMT).

“The wreckage of the tricycle used by the bomber was there. I saw the charred body of the bomber,” said Usman Ali, adding that he saw rescue workers removing bodies from the scene.