Libya's government water supply department on Tuesday warned against repeated attacks on water wells by armed groups, according to the official Libyan news agency.

The spokesman of the man-made river department said "repeated armed attacks on water plants reduced water supply to many cities."

The spokesman confirmed that "more than 73 wells are out of service, causing a loss of more than 400,000 cubic meters of water daily and around 35-percent of water production sources."

On Monday, unknown gunmen forced workers of a water supply plant in the city of Tarhuna, some 80 km southeast the capital Tripoli, to shut down the plant, without specifying any reasons, the department said.

Gunmen repeatedly shut down water supply plants to pressure authorities to meet their demands.

The water pipeline system, which was made during former Libyan leader Gaddafi's rule in 1984, supplies western and eastern Libya with fresh water from the south.