"Punjab Home Minister Shuja Khanzada has embraced martyrdom," said chief rescue official Mohammad Ashfaq.
Khanzada, 71, had been holding a meeting with local people. He was trapped with several others under the rubble after the blast brought down the roof of the building in the village of Shadi Khan in Attock district. "The death toll has risen to 11, including the minister and two police officials," Mushtaq Sukhera, provincial police chief, told AFP.
Twenty-two people had been taken to hospital, he said, adding that the body of the suicide bomber was also found.
Khanzada had been active in crackdowns on sectarian militants and Taliban insurgents in Punjab.
Khanzada, a retired army colonel, had been a member of the Punjab assembly since 2002 and an active member of the Pakistan Muslim League (Nawaz).
The prime minister, along with President Mamnoon Hussain and army chief General Raheel Sharif condemned the attack and expressed their resolve to fight terrorism.
"Such dastardly coward attempts can't dent our national resolve to eliminate the menace," said army spokesman Major General Asim Bajwa in a statement. "Khanzada Shaheed (martyr) was a bold officer whose sacrifice for the greater cause of cleansing Pakistan won't go to waste."
Punjab's government announced a three-day mourning period in the province starting Monday.
Officials said there were up to 40 people in the compound when the suicide bomber blew himself up, causing the entire roof slab to fall in one piece - complicating rescue efforts.
A specially-trained team of army rescuers with modern equipment was working with civilian rescuers to lift and cut sections of the fallen roof to reach the victims.
A police spokeswoman said two police officers were also among the dead in the attack, 70 kilometres (43 miles) north-west of Islamabad.
In the past year Pakistani authorities have cracked down hard on the myriad insurgent groups that have plagued the country for a decade. The offensive intensified after Taliban gunmen slaughtered more than 130 children at a school in the northwest of the country in December.
Last month Malik Ishaq was shot dead along with fellow Laskhar-e-Jhangvi (LeJ) militants, including senior commanders, in Punjab.