Ten people were killed in twin suicide bombings in Potiskum, northeast Nigeria, a police source and a civilian vigilante assisting the military against Boko Haram told AFP on Monday.

Eight vigilantes were killed in the first blast in the Igwanda area of the city at about 12:15 pm (1115 GMT) while two died in the second outside a tavern and brothel in the Dorawa area.

A gunman opened fire on Friday outside a school in northeast Nigeria's city of Potiskum, seriously wounding 12 students in an area repeatedly targeted by Boko Haram, a police officer and witnesses said.

"We have evacuated 12 people with serious gunshot wounds to hospital from the scene of the shooting attack," said the officer, who requested anonymity.

Two blasts rocked bus stations in embattled northern Nigeria on Tuesday, killing at least 27 people, as relentless attacks persist less than five weeks from general elections.

The first, which killed 17 people was caused by a bomb that ripped through a station on the outskirts of Potiskum, in northeast Yobe state, which has been targeted repeatedly by Boko Haram Islamists.

A suicide bomber killed four people and wounded dozens Sunday in an attack at a bus station in Potiskum, northeastern Nigeria, police and hospital sources told AFP.

The town has come under frequent attack by Boko Haram militants and was the scene last Sunday of a bombing in a crowded market carried out by two female suicide attackers, one believed to be aged around 15.

A series of attacks by suspected Boko Haram Islamists in northeast Nigeria has killed a number of people and destroyed several buildings, residents and authorities said Friday.

Explosions and gunfire that started late Thursday shook the city of Potiskum, with residents reporting several schools and a government building burnt, along with a number of dead.