ABIDJAN, June 29 (Xinhuanet) -- A United Nations helicopter crashed in Sierra Leone on Tuesday morning, killing all 24 people on board, reports reaching here said.

    Victims aboard the Russian-made MI-8, belonging to the Siberian-based UT Air charter company, included three Russian crew members,several Pakistani peacekeepers and local aid workers, said Sheila Dallas, a spokeswoman for the UN peacekeeping mission in Sierra Leone (UNAMSIL).

    She said the helicopter, carrying aid supplies on a routine morning flight to the eastern town of Yengema, took off at 8:00 a.m. (0800 GMT) from Freetown, capital of the west African country.

    Air operations lost contact with the helicopter around 9:17 a.m.(0917 GMT) and another three helicopters were sent to conduct a search mission five minutes later, Dallas added.

    Rescue aircraft spotted the burning wreckage of the aircraft at11:27 a.m. (1127 GMT) and reported that there were no survivors.

    Rescuers could not land at the scene because access to the crash site was difficult due to the hilly terrain, but they were trying to reach there on foot.

    In New York, UN Secretary General Kofi Annan's office said the cause of the crash is still unclear, and the world body has launched an immediate investigation into the accident.

    Annan also extended his deep condolences to the families and governments of those who have perished in this tragedy.

    The United Nations started to deploy peacekeepers in Sierra Leone in October 1999. Currently, the UN mission has more than 10,000 peacekeeping personnel, including over 100 Russian peacekeepers. Enditem