BEIRUT -- Hundreds more civilians fled what remained of the Syrian opposition's enclave in Aleppo on Saturday as rebels and government forces exchanged artillery and mortar fire across the northern city.
In central Syria, reports circulated that a government warplane crashed while flying raids against the Islamic State militant group near the historic city of Palmyra.
The group's Aamaq news agency claimed its militants downed the jet near the Jazal oil fields west of the city.
Syrian government forces backed by the Russian military recaptured Palmyra and its famed ancient Roman ruins from the Islamic State extremist group in March.
The Britain-based Syrian Observatory for Human Rights said a government jet crashed in the Jazal area. It reported that Islamic State militants were attacking government positions 2½ miles from Palmyra. The activist-run Palmyra Coordination Committee said the jet was a MiG-23.
The Observatory said Friday that the Islamic State assault near Palmyra has killed at least 49 pro-government forces.
The Observatory reported heavy clashes in Aleppo's southern neighborhoods, but rebels appeared to have held their ground Saturday after two weeks of advances by government forces and allied militias nearly erased them from the city.
Syrian state media said nine civilians were killed in retaliatory rebel shelling on government-held areas of the city. The Observatory reported Saturday that 24 civilians were killed in the previous 24 hours.
Opposition activists accused the government of dropping bombs laden with poisonous chlorine gas on the Kalaseh neighborhood, one of the few still held in the city by the opposition, in the early hours Saturday.
State television station al-Ikhbaria showed footage of hundreds of people carrying children and belongings crossing on foot to the city's government-held areas, where they were being received by state social workers and security services personnel.
The U.N.'s Office for the Coordination of Humanitarian Affairs reported Saturday that the government was confiscating IDs to vet the people seeking refuge. The agency expressed concerns about the vetting process. The U.N. human-rights office has expressed concern about reports that hundreds of men have disappeared after crossing from eastern Aleppo into government-controlled areas.
State media and other outlets loyal to the Syrian government are pushing to show a return to normalcy for Aleppo, delivering on President Bashar Assad's promise to return Syria to the way it was before the six-year war.
But some of those who have already returned to see their homes have broken down at the sight of looting and the damage wrought on the city's eastern neighborhoods.
The government's push, preceded by months of airstrikes that destroyed schools, hospitals and first responder centers, has laid waste to those neighborhoods, which had been held by the opposition since 2012.
Russia's Defense Ministry, which is supporting Syrian government operations in Aleppo, said about 50,000 civilians had fled eastern Aleppo over the past two days The Observatory said "hundreds" have fled in recent days but more than 80,000 have been displaced over the past two weeks. The U.N. estimates the tally at more than 30,000.
U.S. Secretary of State John Kerry and European and Arab diplomats were meeting members of Syria's opposition in Paris on Saturday. Kerry said he is working to ensure their safety and to save Aleppo "from being absolutely, completely destroyed."
Kerry also urged Russia to "show a little grace" in allowing civilians and rebel fighters to safely leave their shrinking eastern Aleppo enclave before the city's inevitable fall.
Information for this article was contributed by Albert Aji of The Associated Press and by Karen DeYoung of The Washington Post.
A Section on 12/11/2016