BEIRUT -- Syrian government forces and Russian aircraft blanketed parts of the besieged, rebel-held enclave of eastern Ghotua with airstrikes and rocket fire on Thursday, activists said, as Syrians marked seven years since the popular uprising that sparked their country's vicious civil war. The assault allowed Syrian dictator Bashar Assad's Russian-backed forces to push further into Ghouta and seize the first major population center there from rebels this week, seemingly sparking a mass exodus of civilians from the town.

A video feed provided by Russian broadcaster Ruptly showed scores of civilians fleeing the eastern Ghouta town of Hamouria on Thursday, seemingly the most significant exodus from the besieged enclave since the Syrian offensive on rebels there ramped up on Feb. 18. The steady flow of civilians came after Syrian government forces reclaimed Hamouria from rebels, with the support of both Syrian and Russian airstrikes.

The final assault to reclaim Hamouria left at least 26 civilians dead on Wednesday, according to the Syrian Observatory for Human Rights (SOHR), a London-based monitoring group which relies on a network of activists on the ground for its information on the war. Images from inside Hamouria showed children among the victims of the airstrikes.

Meanwhile, the International Committee of the Red Cross managed to send a joint relief agencies convoy with aid for thousands of displaced into another part of eastern Ghouta, the town of Douma, the ICRC said.

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According to Syrian Civil Defense, also known as White Helmets, the organization's first responders were unable to reach the wounded in several other towns in eastern Ghouta because of the intensity of the government assault. It said one of its rescue workers was killed in an airstrike on the town of Hazeh.

"They are burning Ghouta to the ground," said Anas al-Dimashqi, a media activist and resident of Kafr Batna, a town also targeted in intense airstrikes Thursday.

Dimashqi, the White Helmets and SOHR reported that government and Russian aircraft were using napalm-like incendiary weapons to spread fires in the towns of eastern Ghouta.

The Syrian government, backed by its allies Iran and Russia, is determined to retake control of the sprawling suburbs of eastern Ghouta, which was a largely agricultural area before the war, just outside Damascus.

Now entering its eighth year, the complex civil war has left more than 465,000 Syrians dead, more than 1 million injured, and forced more than 12 million -- half of the country's pre-war population -- to flee their homes.

More than 1,200 people have been killed in eastern Ghouta alone since pro-government forces launched their assault on the region more than three weeks ago.

Damascus and Moscow have ignored a Feb. 25 U.N. Security Council resolution demanding a ceasefire for the entire country.

The eastern Ghouta region was one of the hubs of the uprising against Assad's rule in 2011 and was quickly targeted for siege, mass arrests, and extrajudicial killings by security forces.

Government forces cleaved the region in two parts earlier this week, and isolated the area's largest town, Douma, from the rest of the suburbs. Douma has seen four days of relative calm, said local media activist Youssef Boustani.

The 25-truck aid convoy organized by the international Red Cross, the Syrian Red Crescent, and the United Nations crossed into eastern Ghouta on Thursday, according to the ICRC, and was expected to deliver aid later in the day.

Damascus routinely blocks the aid agencies from delivering relief to opposition-held areas in the country.

The Russian military, meanwhile, said it had extended a "humanitarian pause" to operations targeting Douma through Thursday and Friday. It claimed the pause has allowed growing numbers of civilians to reach safety.

Maj. Gen. Yuri Yevtushenko was quoted by the Interfax news agency as saying that 131 people left the area through the humanitarian corridor on Wednesday. Maj. Gen. Vladimir Zolotukhin said some 100 people are expected to be evacuated on Thursday.