At least 40 people are dead and scores of others are injured after a series deadly blasts ripped through Aleppo, the largest city in Syria.

Five explosions were reported, all of them near government buildings on the fringe of Aleppo's Old City.

Four blasts occurred in Saadallah al-Jabari Square, close to a military officers' club and a hotel, while the fifth blast occurred a short distance away.

The explosions took place in quick succession, and all are believed to been caused by car bombs.

Television footages showed rescuers pulling out dead bodies from the rubble of ruined buildings, and it is reported that the explosions left a huge crater in the ground.

One resident said the explosions were "like a series of earthquakes. It was terrifying, terrifying." Another witness, known as Hassan, told the AFP that "we heard two enormous explosions, as though the gates of hell were opening.

"I saw thick smoke, and I helped a woman on the pavement whose arms and legs were completely dislocated."

Syria's state television, which is loyal to President Bashar al-Assad, blamed "terrorists" for the attack.

Assad's forces have been fighting rebel forces for control of Aleppo over several months, although neither side has been able to gaining a clear edge over the other.