“Around 90 people were killed when a Nigerian airforce plane circled twice and dropped two bombs in the middle of the town of Rann, which hosts thousands of internally displaced people,” MSF said in a statement.

Locals and community leaders claim the death toll is higher, putting the figure at 170, the statement said.

Bruno Jochum, MSF general-director, said in the statement: “This figure needs to be confirmed. The victims of this horrifying event deserve a transparent account of what happened and the circumstances in which this attack took place.”

On Thursday, authorities opened a probe into the airstrike said to be carried out “by mistake” by a Nigerian fighter jet. According to the military, the jet intended to target a gathering of Boko militants in Kala Balge area of the restive Borno state.

A six-man panel is expected to submit its report into the incident on Feb. 2.