BEIRUT — Rockets fired on a market in a government-controlled neighborhood of Damascus on Tuesday killed 35 people and wounded more than 20 others, Syrian state-run media said, marking one of the highest death tolls in a single attack targeting the capital.
The government blamed rebels in the eastern suburbs of Damascus for the attack on the Kashkol neighborhood. The capital, seat of President Bashar Assad’s power, has come under increasing fire as government forces continue to pound rebel-held eastern Ghouta, with military backing from Russia.
With government forces tied up in the monthlong offensive on eastern Ghouta, Islamic State militants seized a neighborhood on its southern edge, forcing the government to rush in reinforcements.
Islamic State militants captured the neighborhood of Qadam late Monday, a week after rebels had surrendered it to the government. At least 36 soldiers and pro-government militiamen were killed in the clashes, according to the Britain-based Syrian Observatory for Human Rights.
Last year, the Islamic State group lost the swath of territory it had controlled in eastern Syria since 2014 — and where it had proclaimed its self-styled ‘‘caliphate’’ — but it retains pockets of control across Syria, including two neighborhoods on the southern edge of Damascus.
On Monday, the militants pounced on Qadam from the neighboring Hajr al-Aswad and Yarmouk neighborhoods, which they control. More than 1,000 rebels and their families had earlier fled Qadam for rebel-held territory in the north of the country, instead of submitting to the Damascus authorities.
There was no comment from the Syrian government following the seizure of Qadam.
The government’s assault on eastern Ghouta has displaced 45,000 people, the United Nations said Tuesday, while tens of thousands more are living in desperate conditions in northern Syria, where a Turkish military campaign is underway.
In eastern Ghouta, rescue workers were still retrieving bodies from the basement of a school that was bombed Monday by government or Russian jets, a spokesman for the Syrian Civil Defense group said.
The bodies of 20 women and children were retrieved from the rubble, said the group, also known as the White Helmets. The school in the town of Arbin was being used as a shelter by residents.
Oways al-Shami, the Civil Defense spokesman, said continued bombing was slowing down rescue operations.
‘‘They’re not able to use their heavy vehicles because the planes are targeting the civil defense directly,’’ Shami said of the rescuers.
Government forces abruptly intensified their fire on Douma on Sunday after a six-day reprieve allowed a limited number of medical evacuations. In the meantime, they made sweeping advances against other areas of eastern Ghouta, leaving just a fraction of the enclave still outside the government’s control.
A spokesman for the UN refugee agency, Andrej Mahecic, said in Geneva that although tens of thousands have fled eastern Ghouta, thousands more were ‘‘still trapped and in dire need of aid.’’
