Clashes intensified between ISIS and the regime army in eastern Deir Ezzor province on Monday as the extremist group pressed advances in the southern neighborhoods of the city, sources said.
The regime warplanes have carried out airstrikes on ISIS positions, killing one person.
In return, ISIS has rocked the government-held neighborhoods of al-Joura and al-Qusour with RPG and mortar rounds.
Also, east of the capital, two rebels and a war monitor said a military plane had come down about 50 km east of Damascus on Monday in rebel-held territory near a frontline with government-held land.
"We have brought down a Syrian jet in Tel Dakwa area in rural Damascus and we are searching for the pilot," Saad al Haj, spokesman for Western backed Jaish Osoud al Sharqiya rebel group, told Reuters. Osoud al Sharqiya is one of the main groups fighting in the southeast Syrian Desert, known as the Badia.
Another rebel official, Said Seif from the Western-vetted Ahmed Abdo Martyrs group that operates in the area, said the plane came down in an area 15 kms east of Bir Qasab between Tal Dakwa and Dumair airport.
The Britain-based Syrian Observatory for Human Rights war monitor said a plane was shot down by a rebel group in the area and it is not known if the pilot is dead or alive
