Dozens killed in Nigeria bomb attack

Dozens of people have been killed in a bomb attack in north-eastern Nigeria, on a bridge leading to the border with Cameroon.

The improvised explosive device detonated on Monday evening in the town of Gamboru in Borno state killing at least 30 people, the Reuters news agency reports.

Dozens were injured in the blast.

No group has said it carried out the attack but the town is in an area where the militant Islamist group Boko Haram has waged a decade-long campaign of violence.