ISLAMABAD, June 23 (Xinhua) -- At least six people were killed and 20 others injured including two children in a suicide blast near a police check post in Pakistan's southwest city of Quetta on Friday morning, officials said.

Spokesperson of Pakistan's southwest province of Balochistan, Anwaar ul Haq Kakar, said that so far six bodies and 20 injured have been brought to two different hospitals in Quetta, provincial capital of Pakistan's southwest province of Balochistan.

Medical Superintendent of the Civil Hospital of Quetta, Farid Ahmad, said that the death toll might further rise as seven of the injured are in critical condition.

A state of emergency have been declared in all the hospitals in the city.

Deputy Inspector General of Police, Abdul Razzaq Cheema, said that the incident took place Friday morning when a suicide bomber set off his explosives-laden vehicle at a check post near the office of police chief of the province.

"We assume that the bomber wanted to reach the police chief office to attack it, but when policemen at the check post stopped the car for checking the vehicle was exploded," said the police officer.

Soon after the blast, rescue teams, police and security forces rushed to the site and shifted the bodies and injured to the hospitals.

According to local media reports, at least two policemen are among the dead.

Police and security forces have cordoned off the site and launched a search operation in the surrounding areas.

Bomb Disposal Squad of police is collecting evidences from the blast site to know more about the incident.

The blast destroyed two vehicles parked nearby the post and damaged several buildings including a school which was closed during summer vacations.

Karar said that they had reports of entering of an explosives-laden vehicle into the city and security was at high alert.

No group has claimed responsibility for the blast yet.