Press reports revealed that the bombings witnessed in the Syrian capital of Damascus left over 20 dead persons , as a suicide car bomber pursued by security forces blew himself up in eastern Damascus on Sunday, killing 21 people, in the deadliest attack to hit the Syrian capital in months. 

Syrian state media and the Syrian Observatory for Human Rights monitoring group said security forces intercepted three car bombers on their way into the city early in the morning. State television said two of the vehicles were blown up on the outskirts of the city but a third managed to reach the Tahrir Square district, where the driver was surrounded but able to detonate a bomb. 

There was no immediate claim of responsibility, but previous deadly attacks in Damascus have been claimed by Isis and rival jihadist factions. The UK-based Observatory said 21 people were killed in the bombing, including at least seven members of pro-regime security forces and two civilians. It had not identified the remaining victims. It said at least 12 other people were wounded in the blast. 

The Syrian state news agency Sana quoted an interior ministry statement as saying two of the vehicles had been “destroyed” at a roundabout on the road to the city’s airport. The driver of the third blew himself up while being pursued, it said, “killing a number of civilians, injuring others, and causing material damage to public and private properties.”

In the same context, The self-proclaimed Islamic State Group shot down a helicopter belonging to the Syrian regime forces, using a remote controlled-rocket, near al-Assad Hospital, west of Deir Ezzor, the group’s news agency “Amaq” reported on Sunday.

In a related news, the army aviation carried out several air strikes on the city of Mayadin, east of Deir Ezzor, without causing any casualties. Meanwhile, ongoing clashes are taking place between the Islamic State and Syrian government forces, backed by foreign militia in al-Huwaika neighborhood, in the city of Deir Ezzor, amid mutual shelling. It is noteworthy that the US-led international coalition conducted a violent air strike on the town of al-Haseen in the countryside of Deir Ezzor, killing a family of five civilians.

On the other hand, US-backed fighters pierced militant-held Raqqa from the south for the first time on Sunday, crossing the Euphrates River to enter a new part of the Syrian city, a monitor said. The Syrian Democratic Forces (SDF) have spent months closing in on the Islamic State (IS) group's bastion Raqqa and entered the city's east and west for the first time last month.

On Thursday, the US-backed Arab-Kurd alliance sealed off the militants’ last escape route by capturing territory on the southern bank of the Euphrates. "Today, they entered Raqqa's south for the first time and seized the al-Hal market," Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, said on Sunday.

He said some SDF fighters had advanced north across the Euphrates River, while others had attacked al-Hal from the adjacent district of al-Meshleb in Raqqa's east. "The market is fully under SDF control but IS is waging a counter-attack," Abdel Rahman said. The SDF's Operation Wrath of the Euphrates announced it had captured the al-Hal market on Sunday.