The northern white rhino, believed to be the most endangered large mammal on earth, has survived decades of war-related poaching as rangers fought off gunmen from Sudan and Congo.

But wildlife experts say poaching raids in the Garamba National Park have become so intense over the past year that moving the animals to sanctuary in Kenya until their habitat is secured is the only way to guarantee their survival.

There are reports of a few white rhinos outside the park but the total number left in the wild is believed to be less than 10. Another 10 live in captivity but are not reproducing.

Congo's government had initially approved the move and its apparent U-turn angered conservationists who questioned what it could do to make the park safe in a region where tribal militias, former rebels and traditional warriors roam freely.

"The tourism ministry has done nothing to help the rhinos so I am quite curious as to how people who have had nothing to do with it now think they can turn things around," said one conservationist based in Kinshasa, who asked not to be named.

"The looting of the east of this country for wood and ivory is going unchallenged. How come the tourism minister isn't crying about that?" he said.

Conservationists said raising the issue of sovereignty was misleading and aimed simply at whipping up public opinion. They said the animals would remain the property of Congo and would return once the park was safe.

"It is ridiculous misinformation and stirring up of public opinion (by the government). It is just a rescue operation, nothing more," said another Congo wildlife expert.