TRIPOLI, Feb. 14 (Xinhua) -- A truck carrying illegal immigrants of different African nationalities crashed in northern Libya on Wednesday, killing 21 and wounding 75 others, a local medical source told Xinhua.

The traffic accident occurred in the city of Bani Walid, some 180 km southeast of the capital Tripoli, said Mohammed Al-Mabrouk, director of Beni Walid General Hospital.

These immigrants were on a large transport truck that overturned on the outskirts of the city at 4 a.m., Al-Mabroul cited security reports as saying.

He appealed to the international humanitarian and relief organizations for urgent assistance to the hospital "due to insufficient ability to provide medical services for so many patients at the moment."

"We have transferred a number of critical cases to neighboring hospitals," Al-Mabrouk noted.

Beni Walid is a major point of movement for illegal immigrants from southern Libya to the coast in the north, where they are transported by boats through the Mediterranean to European shores.