At least 25 people are reported to have been killed in an explosion in north-eastern Nigeria's Adamawa state.
Some reports said the blast was caused by a roadside bomb and occurred near the town of Mubi, close to the Cameroonian border.
This week Mubi was recaptured from Islamist group Boko Haram, which controls many towns in the region.
In April, the group kidnapped more than 200 schoolgirls in the town of Chibok, causing international outrage.
A spokesman for the governor of Adamawa state told the BBC that most of the victims of the bomb attack in Marabar-Mubi, about 30km (18 miles) west of Mubi, were civilians, although five of the dead were said to be soldiers.
Earlier reports put the death toll as high as 35.
A witness told the Reuters news agency that several buses caught fire in the roadside explosion.