Syria and Russia have announced agreement on a cease-fire in an area that is a stronghold of opposition forces near the capital, Damascus.
The Syrian military command the Russian Defense Ministry said separately on July 22 that a truce would begin in Eastern Ghouta, one of the last bastions for forces in western Syria fighting against troops loyal to President Bashar al-Assad.
The Syrian army said in a report by the state SANA news agency that after days of heavy air strikes it would "halt fighting in some areas of Eastern Ghouta" from July 22.
But the army said it would "retaliate in a suitable manner to any violation" of the cease-fire.
Activists reported relative calm in Eastern Ghouta on July 22 despite some violations.
Eastern Ghouta is in one of four proposed "de-escalation zones" named in a deal reached in May by allies Iran and Russia, who back Assad's government, and Turkey, which supports the opposition forces.
But the agreement has not been fully implemented due to disagreements on who would monitor the safe zones.
If successfully implemented, Eastern Ghouta would be the second zone in which a cease-fire has come into force.
The first cease-fire for areas in southern Syria was brokered by Russia, the United States, and Jordan.
Meanwhile in Lebanon, a mediator was killed in a second day of fighting between Hizballah forces and extreme Islamic forces on July 22 in the Jurud Arsal area near the border with Syria, officials said.