Islamist-led rebels announced Sunday they had started entering the Syrian capital Damascus, where residents told AFP they heard heavy gunfire.

A war monitor said late Saturday that Islamist-led rebels had entered the strategic city of Homs, on the way towards Damascus where Syria's embattled government said it was setting up an impenetrable security cordon.

Iranian Foreign Minister Abbas Araghchi called for "political dialogue" between the Syrian government and opposition groups after a lightning offensive by rebel forces.

Turkey's foreign minister will meet with his Russian and Iranian counterparts in Doha on Saturday to try to find a solution to the renewed fighting in Syria and avoid chaos on its doorstep.

The three countries have been partners since 2017 in the Astana process seeking to end the civil war in Syria even if they have supported opposite sides on the battlefield.

The prime minister of Qatar says he has seen new momentum in Gaza ceasefire efforts since the U.S. presidential election, with the incoming Trump administration seeking an end to the conflict before it takes office.

Sheikh Mohammed bin Abdulrahman Al Thani, a key mediator in the ceasefire efforts, declined to give specifics of the negotiations but told an international conference in Doha that the gaps between the sides are not large.

Rebels on a lightning advance through Syria said on Saturday they have begun to encircle Damascus as government forces denied they had withdrawn from areas near the capital.

Syrian rebel commander Hassan Abdel Ghani sought to reassure religious minorities on Saturday after Islamist-led fighters snatched key cities and swathes of territory from government control.

Syrian opposition activists said insurgents have captured a main border crossing with Jordan forcing Syrian authorities to leave it.

Shortly afterward, Jordan’s Interior Minister al-Frayeh said the Naseeb border crossing with Syria had been closed because of the security situation on the Syrian side.

Gaza's civil defense agency said 29 people were killed on Friday in Israeli strikes near the Kamal Adwan hospital in the northern Gaza city of Beit Lahia, where Israel is pressing a major offensive.

"At least 29 people were killed and dozens were wounded in the northern Gaza Strip since dawn on Friday as a result of the continuing Israeli shelling around Kamal Adwan hospital," said civil defense spokesman Mahmud Bassal.

A war monitor said Syrian government troops pulled out of the central city of Homs on Friday in the face of an Islamist-led rebel offensive, but the defense ministry denied the report.

"Syrian soldiers have withdrawn from Homs city towards its outskirts," said Rami Abdel Rahman of the Britain-based Syrian Observatory for Human Rights monitor. The ministry later said "there is no truth to news... about the army withdrawing from Homs".