Violence hinders U.N. aid work in Chad, Sudan: UNHCR

GENEVA (Reuters) - Pervasive violence in Darfur and eastern Chad has compromised the U.N. refugee agency's ability to work in the region, U.N. High Commissioner for Refugees Antonio Guterres said on Friday.

"We are limited in our action and that translates itself into an even worse situation for the people we care for," he told a news briefing in Geneva.

"It is really a very difficult area for us to act. But ... until now we have been able to keep our presence in Chad."

The United Nations runs 12 refugee camps in eastern Chad, helping some 213,000 Sudanese refugees from conflict-torn Darfur as well as tens of thousands of Chadians made homeless by violence between President Idriss Deby's troops and rebels trying to end his rule.

Under an agreement signed in late September but announced in Geneva on Friday, Chad pledged 75 new guards to reinforce its current cadre of 200 gendarmes protecting UNHCR's camps and offices in the country's precarious eastern region.

Several aid workers were held hostage in the area near Chad's border with Sudan this week, UNHCR said.

Men wearing military uniforms stormed the compounds of two humanitarian groups and held staff at gunpoint while trying unsuccessfully to steal their vehicles, said Jennifer Pagonis, spokeswoman for UNHCR.

Unidentified armed men stole three vehicles belonging to humanitarian agencies in eastern Chad over the last 10 days, Pagonis said, noting that 40 cars have been seized from aid workers there since November. She did not specify the aid agencies involved.

Security concerns near the border prompted UNHCR to shift 284 Sudanese refugees in the Guereda area to a Chad camp further inland on Thursday, Pagonis said, noting another 900 refugees have also expressed interest in being moved.