ISLAMABAD - At least four people, including two policemen, were killed and 15 others injured in a blast on Monday in Quetta, the provincial capital of Pakistan's southwest Balochistan province, police and health officials said.

Senior Superintendent of Police of Quetta district Zuhaib Mohsin told Xinhua that the blast hit a police vehicle that was on a routine patrol at the Meezan Chowk area of the Qandahari Bazaar of Quetta.

Rescue teams, police and security forces rushed to the site and shifted the bodies and the injured to a hospital.

Waseem Baig, the media coordinator of the health department of Balochistan, told Xinhua that four bodies and 15 wounded victims were brought to the hospital.

The health official feared that the death toll might further rise as some of the injured were in critical condition.

The police officer added that the bomb planted in a motorbike was detonated with a remote-controlled device.

According to the police official, three to four kg of explosives were used in the blast, adding that two vehicles, several motorcycles and nearby shops were damaged in the explosion.

No group has claimed responsibility for the attack yet.

Pakistani Prime Minister Shahbaz Sharif condemned the attack, saying that the ill plans of terrorists will be crushed.

Local defense analysts said that the bomb attack might be the reaction to the ongoing operation against the terrorists in the northwest and southwest regions of the country.

Earlier on Friday, Pakistan's top security committee announced the start of an all-out comprehensive operation to wipe out the menace of terrorism in the country.