Russian forces moved into an opposition enclave in the Syrian city of Deraa on Tuesday to try to avert an army assault on a stronghold that has defied state authority since it was retaken three years ago, witnesses, residents, and army sources said.
Their entry brought a halt to shelling by pro-Iranian army units who have encircled the enclave, where protests first erupted in 2011, and had attempted to storm the area on Monday in the latest drive to force former rebels to surrender.
The Syrian army, aided by Russian air power and Iranian militias, in 2018 retook control of the province of which Deraa is the capital and which borders Jordan and Israel's Golan Heights.
Local officials and army sources say the Iranian-backed army units have been pushing for a major new offensive.
However, Moscow gave guarantees to Israel and Washington in 2018 that it would hold back Iranian-backed militias from expanding their influence in the strategic region.
That deal forced thousands of mainstream Western-backed rebels to hand over heavy weapons but kept the army from entering Deraa al Balaad.
On Tuesday, dozens of Russian military police were seen patrolling neighbourhoods of Deraa al Balaad - the centre of the first peaceful protests against the Assad family rule, which were met by force before spreading across the country.
Russian generals presented local leaders and the army with a road map on Aug. 14 to head off any showdown and have been trying to win over the opposition, some of whom fear the plan reneges on the 2018 deal.
Moscow's plan, seen by Reuters, offers ex-rebels a pardon but allows the army to gradually take over the enclave, while offering safe passage to former rebels who oppose the deal to leave for opposition areas in northwest Syria.
Russian troops were accompanied by a group of former Western backed mainstream rebels now integrated in a division of the army known as the Eighth Brigade under Russian command, residents said.
The enclave and other towns in southern Syria have continued to hold sporadic protests against President Bashar al Assad's rule that are rare in areas under state control.