Syria has denied reports that President Bashar al-Assad's deputy has defected.

A statement has been issued saying that Vice-President Farouq al-Shara "never thought for a moment about leaving the country".

Assad, battling a 17-month-old rebellion led by Syria's Sunni Muslim majority that has escalated into civil war, has suffered a string of defections including his prime minister Riyadh Hijab two weeks ago.

Shara, whose cousin, an intelligence officer, announced his own defection last Thursday, is a Sunni Muslim from Deraa province. 

The 73-year-old former foreign minister kept a low profile as the rebellion mushroomed.

Last month he appeared in public at a state funeral for three of Assad's top security officials killed in a bomb attack in Damascus.

However, state media said the vice president had been working since the start of the uprising to reach a political solution to end the bloodshed.

Meanwhile, The Syrian Observatory for Human Rights said the army bombarded neighbourhoods in Aleppo, Syria's largest city.

Rebels hold several districts in the country's northern commercial hub and have tried to push back an army counter-offensive.

State television said soldiers "cleared terrorists and mercenaries" - terms used by the authorities to describe Assad's armed opponents - from the western district of Saif al-Dawla, where some of the heaviest fighting has taken place.

Internet footage which activists said was filmed in Saif al-Dawla today showed a plane making a low pass over buildings and dropping two bombs.

Reports from Syria cannot be independently verified as state authorities have barred international journalists and rights groups.