The U.N. refugee agency says it will continue its operations in eastern Chad but take heightened security measures to protect its staff following the murder Thursday of a French aid worker. The humanitarian organization, Save The Children, has suspended its work in the region pending an investigation into the killing of its staff member. Lisa Schlein reports for VOA from UNHCR headquarters in Geneva.

Save the Children aid worker, Pascal Marlinge, was killed by a group of armed men while traveling in a three-vehicle convoy in eastern Chad near the border with Sudan. The killers are believed to be bandits.

The United Nations says this is the second humanitarian worker killed in Chad in less than a year. In early December, a UNHCR staff member was fatally shot in southern Chad.

U.N. refugee spokeswoman, Jennifer Pagonis, tells VOA the killing of an aid worker is always a shocking event, one that forces humanitarian agencies to evaluate their situation.

She says when tragedy strikes, the UNHCR and other humanitarian agencies operating in the region have to balance the security and safety needs of their staff against the huge needs of the refugees and displaced people."

"We have to look at the overall situation. There is over 240,000 refugees from Sudan's Darfur region and 12 camps run by UNHCR in eastern Chad," she said. " And, there is also 180,000 Chadians who have been displaced by ethnic violence in their own country. So, this is a huge number of people living in very difficult circumstances and simply their needs are overwhelming and they have to be met."

Earlier this year, the UNHCR and other agencies withdrew more than 40 aid workers from the eastern Chad town of Guereda following a series of armed attacks in the area.

Pagonis says the situation has calmed since then, but the border area between Chad and Sudan remains volatile and insecure, with armed gangs roaming around.

"This is one of the most difficult environments anywhere in the world for the UN refugee agency to be working," she said. "These camps are strung out over a 600-kilometer border. Some of them are completely arid and very sort of wind blown, deserted and barren areas. Life is incredibly tough for the refugees and it is also tough for the people trying to help them."

Pagonis says security problems in this region are a fact of life and aid agencies have to adapt to the constantly changing circumstances. Sometimes, she says, this means relocating staff to safer areas until the emergency is over. But, right now, despite the killing of the French aid worker, she says the situation is reasonably stable.