At least 20 people were killed and more than 130 injured in a powerful blast on Thursday in Karachi.

The blast occurred in the office of CID civil lines and the building was completely destroyed as a result 20 people were killed and more than 130 injured including children and ladies.

Five bodies and 95 injured were shifted to Jinnah Hospital while 34 injured and two bodies were rushed to Civil Hospital.

The blast was heard in major areas of city.

Home minister Zulfiqar Mirza visited the site and also talked to media. He said that the blast was similar to the blast at Mariott in Islamabad. Mirza also demanded inquiry report from IG Sindh.

Rescue and relief activities have been initiated at the site of the blast. Heavy contingent of police and law enforcement agencies have cordoned off the area after the incident.

The police chief of Sindh province, said 18 people were killed and that the attackers dismantled the security cordon at the department by opening fire on police. "There was an exchange of fire between police and militants. Then it was followed by a truck loaded with explosives," Salahuddin Babar Khattak told reporters at the scene.