At least 15 people were reportedly killed on Tuesday by a bomb blast that shook Maiduguri, provincial capital of Nigeria’s northeastern Borno State.

“Our rescuers have only confirmed the death toll of 15 people and several others injured in the blast that occurred around 4p.m.,” Jubrin Gunda, spokesman for a local vigilante group, told The Anadolu Agency by phone.

Local vigilante Abdullahi Dauda said four dead bodies had been removed from the scene shortly after the blast.

“The military vehicle and ambulance taking the first four corpses were about to go when they found another dead body,” he told AA.

Borno police commissioner Philip Adoda confirmed the blast.

“I can only confirm the blast but the exact casualties figure is still being compiled,” he told AA.

Haruna Dauda, a local resident, said the explosion occurred at about 4pm at the El-Kanemi Cinema Roundabout, not far from the scene of a similar blast that occurred on Saturday.

“I heard the blast. I was in the metropolis when it occurred. Soldiers and an anti-bomb squad immediately moved to the scene,” he told AA.

Ahmed Bulama, a local trader, likewise confirmed the blast.

“It is sad; we’re just coming out of a weekend tragedy when this one comes again,” he told AA.

“We’ve been asked to close our shops for today because of the incident,” said Bulama.

Tuesday’s explosion came four days after multiple blasts killed around 50 people in Maiduguri.

Since then, the military and local vigilantes have stepped up surveillance in the provincial capital.

Boko Haram militants have mounted several attacks on Maiduguri since the beginning of the year.

Nigeria continues to fight a six-year insurgency that has claimed tens of thousands of lives and displaced over one million people from the northeastern region, where the militancy has been most ruthless.

Last year, Boko Haram went from attacking communities and planting bombs to capturing entire towns.

In mid-2014, it declared a self-styled “Islamic caliphate” in areas under its control with its headquarters in Gwoza, a hilly town in Nigeria's northeastern BornoState.

But Nigerian troops – joined by troops from Niger, Chad and Cameroon – have recently rolled back the gains made by the militants, liberating several Boko Haram-held towns and launching fontal attacks on the group’s hideouts.

Recently, the militants have resorted to attacking soft targets and crowded places with suicide bombers.

•Photo shows scene of a bomb blast.