An explosion targeted a passenger-filled taxi in northeastern Nigeria's largest city on Wednesday, killing eight people in the deadliest bombing there in several months, officials said.

According to AP, the National Emergency Management Agency said in a statement that 15 people had been hospitalized with injuries.

No one immediately claimed responsibility for the blast.

The blast occurred as the taxi approached a gas station in the outskirts of Maiduguri. The bodies of victims were sprawled on the ground next to the bombed-out vehicle as officials inspected the area.

It was unclear if a bomb had been planted in the taxi or if a passenger detonated explosives.

President Muhammadu Buhari recently painted an optimistic picture of the military campaign against Boko Haram. In a speech on Oct. 1 marking the anniversary of the country's independence from Britain, he said the insurgent group "was defeated" in December and that residents of the northeast enjoyed "relative safety" as they went about their daily lives.