Geneva - The UN refugee agency (UNHCR) said Friday it had reduced its activities in eastern Chad on the Sudanese border because of increasing violence.

On Wednesday, two gendarmes guarding the Touloum refugee camp were murdered by three armed men.

The incident followed two hijacking incidents on Tuesday when three armed men stole a vehicle which they drove 45 kilometres to Am Nabak refugee camp. They then hijacked a second vehicle. They finally fled on foot after being chased by gendarmes.

UNHCR said there had been a spate of incidents in the last three months.

On May 1, the head of the Save the Children country mission Pascal Marlinge was shot dead.

Between October 2005 and March 2008 a total of 82 vehicles for humanitarian work had been stolen in eastern Chad. Only 23 had been recovered.

UNHCR feared the recent attack on Khartoum by rebels could trigger further security problems and was now carrying out only essential tasks. (dpa)