The managers of a national park in Congo say poachers killed three rangers and one Congolese military colonel who were part of a 10-man patrol that tracked the satellite collar of a killed elephant to a poachers' camp.

African Parks, a non-profit group based in Johannesburg, said Friday that the anti-poaching patrol was forced to disperse in the Oct. 5 clash in Garamba National Park and that a park helicopter was also hit by gunfire.

Garamba has long been vulnerable to poaching because of regional conflict and armed groups operating in the area.