The World Wide Fund for Nature (WWF) says the continuing fighting in the Democratic Republic of Congo could consign the country's white rhinoceros population to the history books.

WWF is worried at the increased violence in the rhino sector of Garamba national park, in the north east of the DRC.

It says there was an attack on 27 November on a park ranger patrol looking for signs of the last northern white rhinos in the wild.

Park staff in the area say the attackers appeared to be part of a group linked to the Sudanese People's Liberation Army (SPLA).

Highly endangered

Three guards were wounded in the attack, one of them by gunfire.

When WWF carried out the last aerial rhino count in Garamba, in May this year, it found just 25 animals, making the northern white one of the most endangered rhino subspecies.

Like all other wild rhinos, the animals are a target for poachers who sell their horns on the international market.

The demand for rhino horn is undiminished

Rhino horn is still prized for use in ceremonial dagger handles in some Middle Eastern countries, and is in great demand in the Far East.

There it is ground up and used in a number of traditional medicines.

WWF is afraid that the combination of large numbers of firearms with a severe reduction in patrolling and conservation work in the national park could mean that time has run out for the northern white rhinos.

"The situation is critical", said WWF's director-general, Dr Claude Martin.

Appeal to fighters

"This attack and the fact that it happened in the heart of the rhino territory lead us to believe that the world may have to prepare itself for the loss of a unique rhino sub-species.

"We are calling on the forces of the SPLA and the Ugandan army to do everything in their power to reduce the risk of this extinction taking place."

Dr Martin said it was impossible to know exactly what was happening in Garamba.

Global populations are plummeting

"We have received indirect reports of some rhino deaths, but the current state of affairs makes verification impossible", he said.

The southern white rhino, found mainly in parts of southern Africa, is far more numerous than its northern relative.

Africa is also home to black rhinos, found in the south of the continent, and in Kenya and Cameroon.

There are also three Asian subspecies, all of which face similar threats to their survival in the wild.