An attack by Islamic State on the eastern Syrian city of Deir ez-Zor has left at least 85 civilians and 50 government troops dead, a monitoring group has said, with state media denouncing a “massacre”.
Syria’s state news agency Sana, quoting residents, said up to 300 civilians were killed in the onslaught.
If confirmed it would be one of the highest tolls for a single day in Syria’s nearly five-year war.
The bloodshed in Deir ez-Zor came as regime forces battled Isis in the northern province of Aleppo, killing at least 16 jihadis, and as airstrikes hit the Isis stronghold of Raqqa.
The British-based Syrian Observatory for Human Rights (SOHR) said Isis had advanced into the northern tip of Deir ez-Zor and captured the northern suburb of Al-Baghaliyeh.
Initially, it reported that 35 Syrian soldiers and allied militiamen had been killed in the multi-front attack, which included a suicide bombing.
But as the day unfolded, the death toll rose, with the Britain-based monitor saying that civilians were among those killed in Deir ez-Zor.
It said most of the victims were killed “execution-style” in Al-Baghaliyeh. Quoting local sources, Sana denounced the mass killing.
“The [Isis] terrorists carried out a massacre in Al-Baghaliyeh, claiming the lives of around 300 civilians, most of them women, children and elderly people,” the agency said.
It quoted the Syrian prime minister, Wael al-Halqi, as saying that the “legal and moral responsibility for this barbaric and cowardly massacre ... lies on the shoulders of all the states that support terrorism and that fund and arm takfiri [Sunni extremist] groups”.
According to the SOHR, the advance puts Isis in control of around 60% of Deir ez-Zor city, capital of the province of the same name in an oil-rich region bordering Iraq.
Local media later reported that the Isis attack had been repelled.
Isis said its fighters carried out several suicide bombings against regime forces in Deir ez-Zor and seized control of Al-Baghaliyeh and other areas.
The SOHR said Russian warplanes were carrying out heavy airstrikes in support of regime forces as they sought to repel the jihadis.
Regime troops were also locked in fierce clashes with Isis in Aleppo province, with at least 16 jihadis killed after a failed attack on a government position near the town of Al-Bab, the monitor said.
State television also reported that regime forces had repelled an assault in the town.
The Observatory said heavy fighting in the area was going on throughout Saturday, with Russian warplanes carrying out strikes in the region between the regime-held Kweyris airbase and Al-Bab.
The regime has advanced towards the town, an Isis bastion, in recent days, and was within six miles (10km) of it, the SOHR said.
The fighting in Al-Bab is just one of up to seven fronts on which regime forces are seeking to advance in Aleppo province, capitalising on a Russian air campaign that began on 30 September.
The battles are intended in part to cut rebel supply lines into Aleppo, the provincial capital and Syria’s second city.
Aleppo itself is divided and regime forces are now hoping to encircle the opposition-held east.
In addition to cutting rebel access to eastern Aleppo city, the regime was hoping to sever areas controlled by Isis in the province from its territory in neighbouring Raqqa, SOHR spokesman Rami Abdurrahman said.
Raqqa, the self-declared capital of Isis, has come under frequent airstrikes by the US-led coalition, the Syrian air force and Russian warplanes.
On Saturday at least 16 people, including civilians, were killed in air strikes and 30 others were wounded, said Abdurrahman.
He said eight strikes hit the city and its surroundings but did not specify who carried them out.
The British foreign secretary, Philip Hammond, in comments reported on Saturday, said about 600 Britons had been stopped from going to Syria to join Isis and other jihadi groups.
Hammond said these interceptions as well as airstrikes were placing extra strain on Isis in its Raqqa headquarters.
