Civilian deaths mount as Aleppo siege by Syrian forces advances

Syrian government forces advanced Tuesday on Aleppo's old quarter, as the civilian death toll mounts in the ferocious siege to retake sections of the city from rebel groups.

Syrian state TV reported that the government captured several buildings in the old quarter, which is home to the Umayyad Mosque, a UNESCO world heritage site, the Associated Press reported.

Government troops also captured Farafra, a central-held rebel area of the city, state TV said.

Over the past week Aleppo has endured the worst aerial onslaught in the five years of Syria's civil war, with more than 200 people killed and many buildings flattened.

The Britain-based Syrian Observatory for Human Rights, which relies on a network of activists inside Syria, confirmed that government forces are advancing on the old quarter. The group said 11 people were killed Tuesday in airstrikes on rebel-held eastern Aleppo, the AP reported.

Thousands of civilians remain trapped in Aleppo, days after Syrian President Bashar Assad began a new offensive to seize areas around the country's third largest city. A Russia-U.S. brokered cease-fire deal for Syria broke down last week.

U.K. foreign minister Johnson rips Russia for possible Syria 'war crime'

German Chancellor Angela Merkel said Tuesday that talks are urgently needed to bring back cease-fire for Syria. “What we currently see on the ground is very, very brutal and clearly targeting civilians,” she told reporters in Berlin. Developments in recent days have been a “deep, deep setback,” Merkel added.

On Monday, British Foreign Secretary Boris Johnson said last week's attack on an aid convoy near Aleppo that killed at least 20 people would "constitute a war crime" if it was deliberate.

Samantha Power, the U.S. ambassador to the United Nations, accused Russia, an ally of Assad, of "barbarism" for its airstrikes on Aleppo during a U.N. Security Council emergency meeting on Sunday.

"Instead of helping get life-saving aid to civilians, Russia and Assad are bombing the humanitarian convoys, hospitals and first responders who are trying desperately to keep people alive,” she said.

Russian presidential spokesman Dmitry Peskov criticized the U.S. and Britain for comments "capable of causing serious harm to the resolution process."

Contributing: Kim Hjelmgaard