The Nigerian air force accidentally killed at least 52 people and wounded 120 at a camp for internally displaced people in the northeast during an airstrike Tuesday against Islamist militant group Boko Haram, the medical aid group Médecins Sans Frontières said.

Regional military commander General Lucky Irabor said the strike took place early Tuesday in Rann, in Borno state.

“Somehow, some civilians were killed. We are yet to ascertain the number of persons killed in the air strike,” Irabor told reporters in the northeastern city of Maiduguri.

“Many civilians including personnel of International Committee of the Red Cross and Medicins Sans Frontieres were wounded,” he said. Irabor added the air force had acted on information that Boko Haram militants were in the area.

“This large-scale attack on vulnerable people who have already fled from extreme violence is shocking and unacceptable,” Dr. Jean-Clément Cabrol, MSF director of operations, said in a statement. “The safety of civilians must be respected. We are urgently calling on all parties to ensure the facilitation of medical evacuations by air or road for survivors who are in need of emergency care.”

The organization is providing first aid to the 120 wounded patients in its facility in Rann, the statement said.

Boko Haram has stepped up attacks in the last few weeks as the end of the rainy season has enabled its fighters to move more easily in the bush. The northeast has been the focus of the jihadist group’s seven-year-old bid to create an Islamic caliphate.