An elderly man, carrying a briefcase and a bag full of jam, said he was leaving the neighborhood to move in with his daughter.

"What kind of leader does this to his own people?" the man said as he left his home.

A dark plume of smoke rose in the air near Aleppo's ancient citadel.

At least one rebel-controlled neighborhood was notably calmer, Wedeman said. Shops and bakeries were open, and residents walked the streets.

Clashes raged for hours at various spots near the city center, some close to the presidential palace, said Bashir Al-Hajji, a spokesman for a Free Syrian Army brigade in Aleppo.

As rebels scrambled to fend off regime forces in Aleppo, fighting was reported in other parts of Syria.

At least 161 people were killed in fighting across the country Monday, the opposition Local Coordination Committees of Syria said. The deaths included 54 people killed in fighting and the discovery of 20 bodies in Aleppo, the group said.

CNN can not independently confirm reports of violence, as the government has severely restricted access to Syria by international journalists.

There were reports of a bombing Monday inside the Syrian state-run TV building in Damascus, the latest in a series of attacks to rock the nation's capital city as Syrian rebels and government forces battle for control of the country. There was no immediate claim of responsibility for the blast.

"There are some injuries, but Syrian media will continue to broadcast," the Ministry of Information said on state-run TV.

Three Iranian prisoners were killed in the Damascus suburbs during heavy shelling Monday, according to the LCC. The opposition network did not provide additional details.

State media reported over the weekend that "armed terrorists" had attacked and kidnapped 48 Iranian Shiite pilgrims on a bus near the capital.

Roughly 17,000 people have been killed since the Syrian conflict first flared in March 2011, when government forces began cracking down on protesters, Ban said last month. The opposition put the toll at more than 20,000.