 "Seven killed in Pak as blast hits Punjab Home Minister's office")
The blast brought down the roof of the building and around 20 to 25 people, including the minister, were buried under rubble.
Seven persons were killed in the blast, Dawn reported.
Khanzada was in the office at the time of the blast and he was buried under the rubble, his son Sohrab Khanzada told Geo News.
The nature of the blast is not yet known, though some witnesses claimed that a suicide bomber blew himself up.
Khanzada was given charge of the home department in October 2014 and has been actively involved in major operations against terror outfits.