Five Congolese park rangers have been killed in an operation to rescue a US journalist and three other rangers, officials say.
The group had gone missing during a militia attack on the town of Mambasa in the Okapi wildlife reserve, in the north-east of the country, on Friday.
Cosma Wilungula, the head of DR Congo’s park service, told Reuters the gunmen were mining gold inside the reserve.
The mineral-rich east of the country has been wracked by decades of war.
The kidnapping happened when a group of armed men from the Mai Mai militia attacked a group of park rangers accompanying three foreign journalists, Radio Okapi reported.
During the exchange of fire, some of the group, including two Dutch journalists, were able to escape.
The Mai Mai describe themselves as “self defence” groups. Many were armed during the DR Congo war that ran from 1998 to 2003 and were never disarmed.
Park rangers working to protect wildlife regularly clash with the groups, who exploit minerals, wildlife and other resources.
The Okapi reserve covers nearly 14,000 sq km (5,400 sq miles) and protects part of the Ituri forest near the borders with South Sudan and Uganda.