Nigeria Boko Haram attack
Earlier this week, Boko Haram was blamed for a bombing at a shopping complex in the Nigerian capital Abuja. Reuters

Islamist militants are thought to have slaughtered dozens of people in a series of attacks on villages in northern Nigeria.

Gunmen stormed a number of churches near Chibok, in Borno state, where around 200 schoolgirls were abducted by extremist Muslim group Boko Haram in April.

"The attackers went to churches with bombs and guns," Timothy James, a Chibok resident told AFP.

"From what I gathered, dozens of worshippers, including men, women and children were killed."

One of the attacks reportedly took place in the village of Kwadakau, where gunmen opened fire on churchgoers who had gathered for an early-morning Sunday service.

Reuters reported at least 10 people were killed in a single location.

"We cannot tell the number of dead bodies," Chibok leader Enoch Mark said. "I was told the attackers burnt at least three churches to the ground."

Borno is one of three northern Nigerian states at the centre of an Islamist insurgency by Boko Haram - which means "Western education is forbidden" in the Hausa language.

The attack came one day after an explosion blamed on the rebel group at a brothel in Bauchi, north-east Nigeria, killed at least 10 people and wounded 14 others.

Earlier this week, another bomb rocked a crowded shopping complex in the Nigerian capital Abuja, killing at least 21.

Led by Abubakar Shekau, Boko Haram is fighting to turn Nigeria, whose people are almost equally divided between Christians in the south and Muslims in the north, into an Islamic state operating under Sharia law.