Syria civil war
File Picture - Syria Civil War: Aleppo Massacre on Cards, Fears US

In a concerted bid to crush the rebels, Syrian President Bashar al-Assad's forces descended in full might on the country's second city Aleppo.

Taking the civil war to the next level in the 16-month-long uprising, fighter jets were seen over the region while scores of Assad's troops stormed the city. This is the first time fighter jets are believed to have been deployed by Assad's regime in an urban area.

The rebels and the regime's forces have been locked in bitter battles to take control of both Damascus and Aleppo in the last few days.

As the rebels have almost been driven away from the capital Damascus, Assad's troops have now concentrated on Aleppo to wipe out the armed opposition groups.

Artillery fire and rocket barrage have been used by the security forces to pound the whole city, forcing scores of civilians to flee the town. Thousands of residents are streaming out of the country to escape the massive assault.

An unverified video uploaded by activists shows a burning house due to shelling by Assad's forces. Residential buildings were also wrecked in the fighting.

"Military helicopters are flying now over the town. People were awakened by the sound of explosions and are running away. Electricity and telephones have been cut off," one of the activists, Rafe Alam, told Reuters.

Scores of tanks and armoured vehicles from nearby Idlib province have been directed to Aleppo. Nearly 2,000 fully armed troops have been marching into the city.

"People are still in shock that this is happening - they thought it would be limited to one neighbourhood, but it is growing in size to other neighbourhoods. They are scared of chaos and lawlessness more than anything else," Fadi Salem told the New York Times.

According to reports, more than 130 people have died across the country, 20 of them in Aleppo, in the last couple of days.

On Tuesday, heavy firing from helicopter gunships and machineguns was witnessed throughout the day in Aleppo.

It was not yet clear if the fighter jets were used in the latest fighting as contradictory reports emerged. The regime has largely relied on helicopters for aerial attacks on cities.