BEIRUT (AP) -- Pro-government forces pressed on with their offensive targeting the water-rich Barada Valley northwest of the Syrian capital Tuesday, as a group of Syrian rebel groups said they were suspending talks about planned peace negotiations because of what they describe as ongoing government violations of a four-day old cease-fire deal.
The cease-fire, brokered by Russia and Turkey, is to be followed by talks to be held later this month in the Kazakh capital of Astana, between mainstream rebel factions and government representatives.
The U.N. Security Council on Saturday unanimously adopted a resolution supporting efforts by Russia and Turkey, which support opposing sides of the Syria war, to end the nearly six-year conflict in Syria and jump-start peace negotiations.
But the country-wide cease-fire is looking increasingly shaky, with opposition factions angered in particular about the ongoing military offensive in the strategically-important Barada Valley outside Damascus.
In a statement posted late Monday, 10 rebel factions said they are suspending any talks related to the Astana negotiations or any discussions related to the cease-fire "until it is fully implemented." They include the powerful Army of Islam group which operates mainly outside the Syrian capital.
It said the violations in the Barada Valley are continuing and "threaten the lives of hundreds of thousands of residents." The statement also said that the opposition will consider any military changes made on the ground to be a serious violation of the cease-fire agreement.
The Barada Valley, which is controlled by rebels and is surrounded by pro-government forces including the Lebanese Hezbollah group, is the primary source of water for Damascus and its surrounding region. But recent unrest there has resulted in a severe water shortage in the capital since Dec. 22.
Images from the valley's Media Center indicate its Ain al-Fijeh spring and water processing facility have been destroyed, apparently in airstrikes. The government says rebels spoiled the water source with diesel fuel, forcing it to cut supplies to the capital.
The cease-fire agreement is supposed to pave the way for the government and the opposition to meet for talks for the first time in nearly a year in Astana in the second half of January. Those talks will be mediated by Russia, Turkey and Iran, though Russian officials have said other key players including the United States are welcome to participate.