At least 15 people were killed and over 20 others were injured when a blast hit Pakistan's southwestern city of Quetta on Friday night, said local media and police sources.

Local Urdu TV channel Dawn quoted sources as saying that the death toll of the blast has risen to 15.

Earlier District Inspector General Nazir Kurd, top police officer in Quetta, capital city of Balochistan province, said that ten people were injured and some 30 others injured in the blast.

He also told local media that initial information collected showed that the attack was a car bomb blast.

However, a local separatist group Balochistan Liberation Army later claimed the responsibility for the attack and said that it was a suicide bomb attack instead of a car bomb attack.

The group even disclosed the name of the person who carried out the suicide bomb attack as Darvesh Baloch.

The bloody attack took place at about 7:00 p.m. Friday outside a house of a son of a former chief minister of Balochistan province on the Arbab Karam Khan road in the city.

The blast is so huge that it can be heard ten kilometers away from the blast site.

Several houses and a dozen of cars nearby the blast site were seriously damaged, said police.

An estimated 40 to 50 kilograms of explosives were used in the blast, the police said, adding that bomb disposal squad also defused another two bombs planted near the house of the son of the former chief minister.

Police said that Shafiq Mengal, the son of the chief minister, escaped the attack.

The blast was also followed by some firing. One local media journalist was hit by a bullet at the back of his head while covering the incident on the spot. But he was lucky as the bullet only bruised the back of his head and was in a stable condition, a colleague of the injured journalist told Xinhua over the phone.

All the injured have been shifted to civil and military hospitals following the blast. Emergency has been declared in all hospitals in the city following the blast as many people were injured in the explosion.