Damascus: Syrian troops buoyed by victory in Qusayr are preparing to launch a northern offensive, a security source says, as the conflict came to the streets of Beirut where a demonstrator was killed.

At a protest outside the Iranian embassy against the Lebanese Shi'ite group Hezbollah's direct involvement in the Syrian conflict, a man was shot and fatally wounded in the first such shooting in Beirut linked to the 26-month war.

Free Syrian Army fighters rest in Aleppo's Karm al-Jabal district. The Syrian army is expected to target the northern city within days. Credit:Reuters

A Syrian security source said that after capturing from rebel forces the strategic region of Qusayr on the border with Lebanon with the support of Hezbollah fighters, the regime's next target was Aleppo province in the north.

"It is likely the battle for Aleppo will start in the coming hours or days, and its aim is to reclaim the towns and villages in the province," the source told AFP on Sunday on condition of anonymity.