A United Nations helicopter crashed on Friday morning as it was flying over east Democratic Republic of Congo’s North Kivu province, the U.N. World Food Programme (WFP) said.

The United Nations Humanitarian Air Service chopper, managed by the WFP, went down near the city of Goma.

There were no passengers on board and three crew members were injured, the aid agency said.

Without providing further detail, WFP said the cause of the incident was not yet clear.

Eight peacekeepers were killed in March when a U.N. helicopter crashed in the area of Tshanzu, in North Kivu.

That helicopter was on a reconnaissance mission when it went down amid clashes between the Congolese army and a rebel group known as the M23.

Congo’s army at the time said the helicopter was shot down by rebels, which the M23 denied.

The U.N. peacekeeping mission MONUSCO did not state the cause of the crash and said investigations were underway.