A United Nations helicopter has crashed in eastern South Sudan, killing all four crew members onboard, the world body's peacekeeping operation in the country reported today.

"The helicopter was not carrying any passengers," the UN Mission in South Sudan (UNMISS) added in a news statement. "The Mission extends its heartfelt condolences to the families of the crew."

UNMISS has begun an investigation to establish the circumstances around the crash, which occurred near the settlement of Likuangole, the state of Jonglei, in the country's east.