ABUJA (Reuters) - A bomb blast at a bus station in the northeast Nigerian city of Gombe on Monday killed at least 15 people and wounded 21, an official from the emergency services said.
There was no immediate claim of responsibility for the attack. Boko Haram insurgents have repeatedly set off bombs targeting civilians, especially in the remote northeast where they are trying to carve out an Islamist state.
The official from the National Emergency Management Agency (NEMA), who declined to be named, said the wounded were being treated. The blast had been caused by a bomb but it was not yet known whether a suicide bomber was involved.
It was the second such attack on the city's public transport system in as many months. At the end of October, a car bomb at a bus stop killed at least 10 people.
The campaign for an Islamic state by Boko Haram, whose name means "Western education is sinful," has become the gravest security threat to Nigeria, which is Africa's biggest economy and top oil producer.
Thousands of people have been killed and many hundreds abducted, raising questions about the ability of security forces to protect civilians, especially around the Cameroon border in the north where the militants are well established.
Suspected Boko Haram gunmen kidnapped 172 women and children and killed 35 other people a week ago during a raid on the northeastern village of Gumsuri.
Around 200 girls snatched in April by the group from a secondary school in the village of Chibok, also in the northeast, remain in captivity.
(Reporting by Isaac Abrak; Writing by Tim Cocks; Editing by Mark Heinrich)