LONDON - Two British tourists who were kidnapped in the Democratic Republic of Congo have been freed, Foreign Secretary Boris Johnson said Sunday.

"I am delighted to announce that two British nationals who were held hostage in the Democratic Republic of Congo have been released," he said in a statement. "I pay tribute to the DRC authorities and the Congolese Institute for Nature Conservation for their tireless help during this terrible case."

Authorities in DR Congo said the three were kidnapped in the Virunga national park on Friday.

One of the most important conservation sites in the world, it covers 7,800 square kilometres (3,011 miles) along a swathe of eastern DR Congo abutting the border with Uganda and Rwanda. Virunga is home to about a quarter of the world's population of critically-endangered mountain gorillas, as well as to eastern lowland gorillas, chimpanzees, okapis, lions, elephants and hippos.

But it is located in DR Congo's North Kivu province, where armed groups are fighting for control of territorial and natural resources, and poaching is a major threat.