Boko Haram militants have attacked a refugee camp in Nigeria just days after it was mistakenly bombed by the country's air force.

The Islamist group struck as aid workers tried to help victims of Tuesday's airstrike, which Medecins Sans Frontieres (MSF) has said killed at least 90 people.

Residents and community leaders, however, have reported a much higher toll of 170.

Thursday's attack by Boko Haram, the intended targets of the military airstrike, resulted in the deaths of eight militants and left one soldier injured, according to witnesses.

Image: A government spokesperson described the attack as a 'regrettable operational mistake'

"Multiple air-dropped munitions" hit the camp in Tuesday's bombing.


"A Nigerian air force plane circled twice and dropped two bombs in the middle of the town of Rann, which hosts thousands of internally displaced people," MSF said.

"At the time of the attack, an aid distribution was taking place."

Charity workers from MSF and the International Committee of the Red Cross (ICRC) were confirmed to be among the dead and injured.

Human Rights Watch said the strike destroyed 35 buildings.

A spokesperson for President Muhammadu Buhari said it was a "regrettable operational mistake" and has led to an investigation by the Nigerian Air Force (NAF).

Image: People injured in the bombing receive emergency treatment

MSF General Director Bruno Jochum said: "The victims of this horrifying event deserve a transparent account of what happened and the circumstances in which this attack took place."

The area is a stronghold for Boko Haram who are trying to create an Islamic caliphate in the northeast of the country.

The jihadist group's seven-year-old uprising has killed more than 20,000 people and forced 2.6 million from their homes.

They have stepped up their attacks in recent weeks, making use of the rainy season which enables fighters to move more easily in the bush.