At least 32 people, including a PM (Q) candidate, were killed as violence raged on Friday  in several Pakistani cities following the assassination of opposition leader Benazir Bhutto [Images], prompting authorities to deploy the army and issue "shoot-at-sight" orders.

Angry Bhutto supporters went on a rampage looting banks, torching vehicles and an office of President Pervez Musharraf [Images] backed PML (Q) party, burning railway stations and clashing with the police in Sindh, Bhutto's home province which was worst affected by the violence.

Army had been deployed in sensitive areas of Karachi, Hyderabad, Sukkur, Larkana, the hometown of the slain former prime minister, Dadu and Rohri to prevent more loss of lives and damage to public and private property, Sindh's Home Secretary Mohammad Mohtaram said.

He said 23 people, including four security officials, were killed in the riots.

Also, nine persons, including a PML-Q leader, were killed and several others injured in an explosion near an election rally in Pakistan's restive northwestern Swat valley.

Former provincial minister Asfandyar Amirzaib, who is contesting the upcoming polls on a PML-Q ticket, was among those killed when his vehicle was targeted with an explosive device in Mingora, the headquarters of Swat district.

Announcing a judicial inquiry into Bhutto's killing, caretaker premier Mohammad Mian Soomro appealed for calm.

"The death of Mohtarma Benazir Bhutto is a national tragedy and enemies of the country are now trying to instigate the people to violence and instability," he told reporters after a Cabinet meeting reviewed the situation.