Congolese soldiers and park rangers are searching for two British tourists kidnapped in the country’s volatile eastern borderlands, an army spokesman said.
Unidentified armed men on Friday ambushed the tourists' convoy while they were gorilla trekking at Virunga National Park.
One park ranger was killed during the incident in Africa’s oldest national park, while three other people, including the British citizens, were abducted.
The murdered ranger has since been identified as 25-year-old Rachel Katumwa.
“With Virunga National Park being within our zone of action, we have joined the park rangers for search operations for the people taken hostages,” said regional army spokesman Major Guillaume Kaiko Ndjike on Saturday.
The British Foreign Office confirmed it was in contact with the Congolese authorities following the incident and said its staff were supporting their families.
On its website, it has advised against "all but essential travel" to some Eastern cities amid an increase in reports of attacks by armed groups as well as military and police stop-and-search checkpoints.
Rebel groups and militias control large swathes of the country's east and more than 175 rangers have died protecting Virunga National Park, which is adjacent to neighboring Rwanda and Uganda since it was created in 1925.
Yet the area has attracted a growing number of visitors keen to visit its endangered mountain gorillas and the active Nyiragongo volcano.
Reporting by Fiston Mahamba; Writing by Joe Bavier; Editing by Alexander Smith.