The U.N. refugee agency says fear among thousands of people who fled to Chad from Sudan's conflict-ridden province of Darfur is growing in the wake of fatal attacks by janjaweed militiamen on Monday. The agency says the attack occurred near the village of Dolola, in southeastern Chad ,just a few kilometers from a refugee camp at Goz Amir.

The refugees were not the victims of this attack but the U.N. refugee agency says it was too close for their comfort.

UNHCR spokeswoman Jennifer Pagonis says a group of 150 armed men surrounded Chadian villagers early Monday and opened fire, killing four people and wounding five others.

She says the local population described the men as janjaweed militia. The janjaweed, who are Arab fighters supported by the Sudanese government, have been waging war against black African inhabitants of Darfur for the past three years.

Pagonis says the assailants stole about 1,000 head of cattle. She says the wounded were transported to the nearby Goz Amir refugee camp and to the hospital in Goz Beida for treatment. "Goz Amir is one of about a dozen UNHCR-run camps in eastern Chad and is currently home to some 17,700 Sudanese refugees from Darfur. Several hundred internally displaced Chadians have also settled near the camp in recent weeks, having fled earlier janjaweed attacks for the relative safety they hope to find in the refugee camp," he said.

Last month, a large group of armed men briefly took control of the Goz Amir camp, prompting the UNHCR to ask the Chadian government for more security.

Pagonis says the growing number of attacks near the camp is a matter of grave concern.

In recent months, she says the High Commissioner, Antonio Guterres, has repeatedly raised the alarm over spreading insecurity in the remote border regions of Sudan, Chad and the Central African Republic. "Despite the presence of about 18 Chadian gendarmes around each of the refugee camps in eastern Chad, there is a need to further increase security in the region. Local Chadian residents throughout the region are now telling our staff that they are very frightened, and that if humanitarian agencies were ever forced to withdraw from the area, they too would have to move in search of a safer haven," he said.

The UNHCR cares for more than 200,000 refugees from Darfur in 12 camps in eastern Chad. It also assists about 46,000 refugees from the northern part of the Central African Republic in southern Chad.

Pagonis says during the past couple of months, about 10,000 people from Chad have fled across the border to Darfur to escape instability in their own country.