The UN workers were kidnapped in the town of Beni in the eastern Kivu region.

The Congolese Rally for Democracy-Liberation Movemement (RCD-ML) made the announcement one day after the group signed a truce to end fighting with a rival, larger rebel group for control of the mineral-rich region.

The men “disappeared (Thursday) in the evening with neither their personal belongings nor their vehicles,” said a leader of the RCD-ML, which administers Kivu.

"Their belongings were in disarray but there was no blood at their lodgings," he said.

The head of the rebel RCD-ML, Mbusa Nyamwisi, which is allied to the Kinshasa government, said Friday he was "indignant" at news of the kidnapping, which he said could have been carried out by renegade members of his own movement.

There are at least 500 UN military
observers in the DRC

He told the French news agency, AFP that the kidnappers may be members of the RCD-ML

"We are following some serious leads and there is a probability that the kidnappers are members of the RCD-ML who, corrupted by the enemy, have betrayed us,"

The UN has confirmed the kidnappings in the DRC, but has yet to reveal the names of nationalities of the two men. The UN mission has eight military observers of various nationalities in Beni.

The UN is conducting its own investigation into the kidnapping. 

According to figures from April, the UN has 509 military observers, 3,805 troops and 50 civilian police in the former Belgian colony of Zaire.

Mandated in November 1999 by the UN Security Council , the UN mission in the DRC is empowered to deploy military personnel, including observers, to the country.

They are backed by specialists in human rights, child welfare, humanitarian affairs, public information, political affairs, and medical and administrative support.

The war, which officially ended in April when a peace accord took effect, has seen fighting continue to parts of the vast central African country, mainly in the north-eastern Ituri region and in Nord-Kivu.