The Red Cross says six of its employees were shot and hacked to death on Thursday in northeast Congo.

"It's very horrible," said Boni Mbaka, a United Nations official at the scene. "There were no survivors (so) it's difficult to say what happened."

The Red Cross says the team was heading to a remote health centre to deliver medicine and supplies. The bodies were found about 65 kilometres north of Bunia in Ituri province.

They were travelling in two vehicles marked with the Red Cross emblem and were not carrying any weapons.

The area has been the site of fighting between herders and farmers. Both want control of the grasslands in the area.

Humanitarian groups often face charges of favouring one group or another. Still, this particular mission wasn't considered particularly risky. "We didn't consider that a particularly dangerous area," said Paul Castella, the head of the Red Cross delegation in Congo.

The Red Cross says it's stopped all of its operations in east Congo but isn't saying whether it will pull out of the area.

"We need to know more about the circumstances and motives behind the killings before we can evaluate what to do," said Antonella Notari in Geneva, Switzerland.