Insurgents fired mortar rounds at one of President Bashar al-Assad's palaces in the Syrian capital, as the death toll mounts from a devastating missile strike on second city Aleppo.
The shelling, which was claimed by the rebel Free Syrian Army, came as dozens of Russians left the war-battered country on a plane sent from Moscow as its navy reportedly dispatched four warships to the Mediterranean for a larger evacuation.
In Damascus, two mortar shells crashed into an area "near the southern wall of Tishreen palace" and two hospitals, causing damage but no casualties, state news agency SANA quoted an unnamed official as saying on Tuesday.
Little is known about Assad's movements, and Tishreen in west Damascus is normally reserved for dignitaries, but it was the first time his regime has reported shells falling near a palace since the 23-month conflict flared.
The rebel Free Syrian Army said its fighters had "fired mortars at the Tishreen presidential palace", one of three in the capital along with palaces at Mount Qassioun and Rawda.
The shelling came a day after an apparent surface-to-surface missile attack flattened a residential area of Aleppo city, killing at least 31 people, said the Syrian Observatory for Human Rights.
Fourteen children and five women were among the dead, it said, adding the toll was likely to rise as bodies were still under rubble and people were critically injured.
There were no planes overhead when the missile hit, according to residents, and the extent of the destruction indicated a surface-to-surface missile was likely used, the Observatory's Rami Abdel Rahman told AFP.
Abu Hisham, an Aleppo-based citizen journalist, said "housing in the district was informally built. It took one surface-to-surface rocket to destroy an entire neighbourhood".
Video footage and photographs shot by activists in Aleppo, scene of fierce fighting since the army launched an all-out assault to stop a rebel advance on the city on July 20, showed massive destruction in Jabal Badro.
Amateur film posted online by the anti-regime Aleppo Media Centre showed crowds of people gathering around hills of rubble and a bulldozer shovelling the debris as residents searched for loved ones.
Observers are watching for any hints of Russia planning a full-scale evacuation of its citizens, which would be seen as a tacit admission from Moscow that Assad is doomed in his fight against rebels.
Meanwhile, hundreds of troops backed by military vehicles poured into Aleppo province, as rebels clashed with loyalists around Kwayris military airport as they pushed on with an assault to take control of Aleppo international airport.
At least 100 people were killed across Syria on Tuesday, among them 58 civilians, 23 soldiers and 19 rebels, said the Observatory, which relies on a network of sources on the ground for its information
The UN says at least 70,000 people have been killed in the near two-year conflict, and puts the number of Syrians who have fled their homeland at more than 850,000.