The blast came two days before Pakistan's 70th Independence Day, and the military chief said it was an effort to mar celebrations.
"Incendiary explosive was used in the blast due to which nearby vehicles caught fire", ISPR reported. "Our resolve won't succumb to any challenge", Maj Gen Asif Ghafoor tweeted. "At least 32 others are wounded", Balochistan home minister Sarfraz Bugti said.
A spokesman for the Balochistan government, Anwar ul Haq Kakar, also confirmed the death toll. Earlier, several television channels had reported that around 17 dead bodies were brought to the hospital and a lot of them were badly charred and burnt. Medics say some of the injured have life-threatening wounds, while the bodies of the dead are charred beyond recognition. The entire area was cordoned off by police and security forces.
According to the Dawn newspaper, citing Home Minister of the Balochistan province Sarfaraz Bugti, civilians as well as security forces officials are among the victims. "15 people including 7 civilians were martyred", the statement said, adding that 25 people including 15 civilians had been injured and taken to a military hospital.
Casualties were also confirmed by rescue and hospital sources. Rescue services have reached the site and are conducting rescue activities. "The bomb disposal squad has reached the spot and we will be able to confirm soon whether it was a suicide attack or a planted bomb", he said. "Several vehicle and auto rickshaws have been burnt or damaged after the blast as they caught fire due to the intensity of the blast", the official said.
The Balochistan Assembly, Quetta Law College, a private hospital and many offices are located in the vicinity where the explosion occurred.