The death marks the first ranger killed since January in Virunga National Park, which is home to famed mountain gorillas and has lost 140 rangers to violence in the past few years.

“Armed rebels came to attack our position,” Innocent Mburanumwe, a conservation ranger in the park, said in an interview Friday.

The attack happened June 17, as rebels worked to take control of Edward Lake in the center of the park, Mburanumwe said. He said they were driven away after an exchange of gunfire. Ranger Kasereka Sikwaya, known as Timor, lost his life.

“The situation is now very calm and the area is now secure,” says Mburanumwe, who is a National Geographic emerging explorer. The injured rangers are receiving medical treatment. (Contribute to Virunga’s Fallen Rangers Fund.)

The poachers ambushed the men on Wednesday in Garamba National Park and a second ranger was lightly injured in the attack, said African Parks, which is based in Johannesburg. The group manages the Garamba park in central Africa along with Congolese authorities, and also runs seven other parks on the continent.

The Garamba park unit that was attacked had been deployed to reinforce another team that earlier exchanged gunfire with the poachers, African Parks said in a statement.

It said rangers, the military and other security forces were trying to track and arrest the poachers, who are believed to be from South Sudan. The Garamba park is in northeast Congo, on the border with South Sudan.

Garamba has long been vulnerable to poaching, partly because of regional conflict and armed groups that have operated in the area. They included the rebel Lord’s Resistance Army, which used the park as a safe haven. In 2008, the Ugandan army launched an attack on an LRA base in Garamba, throwing the group into disarray.