A senior Syrian rebel official denied a report on Friday that a ceasefire had been reached between rebels and government forces in the Wadi Barada area near Damascus, where bombardments have knocked out the capital's main water source.
The government and allied fighters from the Lebanese group Hezbollah launched an attack two weeks ago to take back Wadi Barada where a spring provides supplies to four million people in the capital.
A military news outlet run by Hezbollah reported that a ceasefire had been reached for "a number of hours" in the area.
But Munir Sayal, head of the political wing of the Ahrar al-Sham rebel group, told Reuters the report was "a lie".
He said that the government had on Thursday rejected a ceasefire that would have allowed for repairs to the water pumping station and for people to return to two nearby villages from which they had been displaced.
Rebels say the government bombed the water pumping station at the start of the campaign. The United Nations has said it was put of action by "deliberate targeting" but has declined to say which side was responsible.