Suspected Islamist insurgents abducted more than 100 female students in a night raid on a government secondary school in Nigeria's northeast Borno state, a teacher has said.

The gunmen are believed to be members of the Boko Haram Islamist group, which has attacked schools in the northeast before as part of their anti-government rebellion.

The group carried off the girls from the school in Chibok, around 140km south of the Borno state capital Maiduguri.

"Over 100 female students in our government secondary school at Chibok have been abducted," said Audu Musa, who teaches in another public school in the area.

The raid took place on the same day as the deadliest ever attack on the capital, Abuja, in which 75 people died.

That attack also raised questions about the government's ability to protect the capital from an insurrection that risks spreading from the Islamist group's heartland in the northeast.

Attacks by Boko Haram, which says it wants to carve out an Islamic state, have targeted police, military and government posts as well as schools and churches.

The group has killed more than 2,000 people in the last six months alone, and left the Nigerian military struggling to respond.