Syrian regime and allied forces battled to suppress the last pockets of resistance in and around Damascus Tuesday while the beleaguered Kurds in the north braced for further Turkish advances.
The simultaneous assaults have sparked one of the worst humanitarian emergencies since the start of the Syrian conflict seven years ago, with aid groups struggling to gain access to the masses of displaced civilians.
Washington has voiced concern that the chaos in Syria could allow a revival of the Islamic State group, whose "caliphate" collapsed late last year after three years of international military operations.
The jihadists launched a surprise nighttime attack in a southern neighbourhood of Damascus, moving into the vacuum left by a deal that saw another armed group pull out exactly a week ago.
"IS took full control of Qadam, and 36 government troops and loyalist fighters have been killed," the Syrian Observatory for Human Rights reported.
There was no immediate comment from the regime, nor could the Britain-based monitoring group provide casualty figures for the jihadists.
Observatory chief Rami Abdel Rahman said the regime was sending reinforcements to retake Qadam, which was attacked from the adjacent IS-controlled neighbourhood of Hajar al-Aswad.
The jihadists also have a presence in the nearby Palestinian refugee camp of Yarmuk.
Assad has in recent months brought swathes of territory back under his control thanks to heavy Russian involvement, as well as support from other forces such as the Iran-backed Lebanese Hezbollah militia.
He has recently focused his efforts on flushing out the last pockets that escape government control in and around the capital, the largest of them being Eastern Ghouta.
A month-long air and ground assault on the area, which was home to around 400,000 residents, has left more than 1,400 dead.
Regime and allied forces have retaken more 80 percent of the enclave and splintered its rump into three pockets, each controlled by a different armed group.
Tens of thousands of civilians have fled both the intense bombardment and the deprivations of a siege that lasted five years.
Eastern Ghouta s main town of Douma remains under rebel control but even as a trickle of emergency medical evacuations was scheduled to continue Tuesday, the regime continued to pound the enclave.
An AFP correspondent reported heavy bombardment through the night, adding that ambulances were struggling to reach the wounded so intense was the shelling.
At the town s main hospital, exhausted staff worked on extracting a palm-sized shard of wood from the head of a 10-year-old girl.
The local civil defence group known as the "White Helmets" said they were able to retrieve only two bodies and that several others remained trapped under the rubble.
Clashes broke out between the Jaish al-Islam rebel group and the regime on the outskirts of Douma, the correspondent said.
The Observatory said 16 children were among 20 civilians killed overnight when an air strike on the town of Arbin levelled the school above the basement they were sheltering in.
Another humanitarian catastrophe was unfolding hundreds of kilometres (miles) to the north near Syria s border with Turkey, whose forces have pressed a devastating offensive.
The United Nations said close to 100,000 people have been displaced by fighting in Afrin district, a Kurdish-majority enclave against which Turkey launched an assault on January 20.
The Turkish army and its Syrian proxies -- a motley assortment of jihadists, former rebels and members of other armed groups -- seized Afrin on Sunday.
On Tuesday, Turkish military police deployed across the city, as a small number of civilians tried to return to homes and shops that had been looted by Turkey s Syrian proxies after their entry into the city, the Observatory said.
The capture of Afrin, one the cantons in the self-proclaimed autonomous administration run by Syria s Kurds, is a huge blow to the minority.
Resentment runs high among the Kurds over the lack of Western support for their fighters, who spearheaded the US-led coalition s efforts against IS for more than three years.
The People s Protection Units (YPG) Kurdish militia redeployed some of its fighters from desert areas in the east where they had been battling remnant jihadists to join the defence of Afrin and the rest of their heartland.
The US has voiced concern over the humanitarian consequences of the Afrin assault by its NATO ally Turkey.
US State Department spokeswoman Heather Nauert warned Monday that it was also distracting from the fight against IS, which she said had begun "reconstituting in some areas."
"This is a serious and growing concern," she added.
