Battle rages in Damascus between Syrian government troops and rebels 1907122.

Defense News - Syria

Columns of black smoke rose over Damascus on Thursday, July 19, 2012, as troops shelled Qaboon and Barzeh, while fighting raged in al-Midan and Zahira and loud explosions were heard in Mashrou-Dumar, said the Syrian Local Coordination Committees.

Violence also erupted in Ikhlas neighbourhood near the government headquarters after rebels attacked forces loyal to Assad, who have deployed armoured vehicles and increased roadblocks across the city.

Al Jazeera's Zeina Khodr, reporting from Beirut, said many people believed the latest developments had led the Syrian conflict to a turning point.

"The Damascus fighting is now in its fifth day, getting close to power base of the Syrian president," our correspondent said. "The prestige of the regime has been shattered. Losing control of Damascus [means] the regime is slowly losing its grip over the country."

Wednesday's attack, the first to target Assad's inner circle since a 16-month uprising erupted, came ahead of a Western showdown on Thursday with Russia and China over a draft UN resolution calling for sanctions.

The explosion was blamed on a bodyguard attending a meeting of security chiefs at their headquarters, prompting the White House to say Assad was "losing control" of Syria.