Residents of the Syrian city of Damascus faced their third consecutive day without water on Sunday after the city's supply was allegedly poisoned.

Authorities cut off the capital city's pipeline following reports that rebel groups had contaminated water supplies with diesel.

The al-Fija spring, which supplies fresh water to Damascus, lies next to the rebel-controlled town of Ein al-Fijeh, in the mountainous Wadi Barada area.

Daily news outlet Al-Watan, which is closely aligned with the Syrian Government, accused groups of "contaminating the water resources into Damascus with pollutants and diesel."

The Damascus City Water Supply and Sewage Authority said in a statement it had halted supplies following "terrorist attacks on all water resources feeding into Damascus and its surroundings".

It said the city was running on reserves and a schedule would determine when it would pump water to different neighborhoods.

"Water has been totally cut for three days," said Rasha, a 51-year-old housewife.

"We can live without electricity but we can't live without water."

News agency AFP reported that two districts received water on Saturday but had run out by Sunday.

The alleged attack came during an offensive on the Barada Valley area by government forces and their allies.

The Barada river is fed by a karst spring in Ain al-Fijah, and Lake Barada (pictured)

The Syrian Observatory for Human Rights said regime forces were shelling the area "to put pressure on Islamist rebel factions and Fateh al-Sham Front to accept a reconciliation deal."

In 2014, some reports said rebel groups had threatened to cut off the water supply and had even threatened to blow the karst spring up.

On Saturday state news agency SANA reported that militants blew up the Barada water pipeline in the suburb of Kafr al-Zayt.

It reported that pipeline was fixed and its service restored on Friday less than a month after a similar attack.

More than 310,000 have died in the six year conflict in Syria and half the population has been displaced.

aw/kl (AFP, AP, Reuters)