BEIRUT — Pro-government forces intensified their assault on the rebel-held suburbs of the Syrian capital, activists said Tuesday, a day after rebels beat back an attempted government advance, killing several soldiers.

The fighting threw into sharp relief the fragility of a so-called “cease-fire” that was supposed to bring calm to the besieged enclave inhabited by some 400,000 people.

Opposition media activist Anas al-Dimashqi said government air raids and artillery fire have reached a rate of 60 to 70 strikes per day on areas held by the Faylaq al-Rahman rebel faction, which was not party to the cease-fire brokered by Egypt and Russia and signed in Cairo on July 22.

Air strikes on the Ein Terma and Zamalka towns in Ghouta blasted debris hundreds of feet into the air, as seen in footage posted by the Ghouta Media Center on social media Tuesday. The opposition-affiliated center said one civilian was killed and several others wounded.

But mortars also fell on Douma, al-Rayhan and Housh al-Douahira, towns and villages held by the Islam Army faction, which is party to the cease-fire, according to al-Dimashqi and the Britain-based Syrian Observatory for Human Rights monitoring group.

The Observatory said rebels killed nine soldiers and captured at least one fighting for the Syrian army’s vaunted 4th Division, in battle Monday. It said the bombardment continued Tuesday.

“What kind of cease-fire is this?” said Observatory director Rami Abdurrahman. “I don’t consider this a cease-fire.”

For its part, Faylaq al-Rahman said it came under attack by the Islam Army over the weekend, it said in a statement Tuesday.

It said in separate statement published Sunday that it would agree to a cease-fire that does not “compromise the principles of the revolution,” but said it was not consulted for the Cairo agreement.

Ein Terma, once home to 40,000 residents, has been largely vacated, according to Mohammad al-Boush, another media activist in Ghouta.

He said civilians across the Ghouta region are in dire need of food and fuel, particularly after government forces seized the Qaboun and Barzeh neighborhoods in northeast Damascus in May. The two neighborhoods were hubs for smuggling supplies into the Ghouta region.