Following news that former Pakistani Prime Minister Benazir Bhutto had been assassinated in a suicide attack, protesters took to the streets and set fire to vehicles in Karachi.
President Pervez Musharraf condemned the killing and urged people to remain calm, but angry protests gripped cities across the country, including Lahore.
Some supporters of Ms Bhutto's Pakistan People's Party torched banners promoting the party allied to President Musharraf, the PML-Q.
Other protesters in Rawalpindi set light to tyres.
Supporters of Benazir Bhutto had gathered outside the hospital in Rawalpindi, where doctors had tried in vain to save the former premier, to express their grief.
Nawaz Sharif, also a former prime minister and a political rival, announced his Muslim League party would boycott coming elections - and joined Ms Bhutto's supporters at the hospital.
The mourners carried Ms Bhutto's coffin from the hospital when her body was released.
They then followed the ambulance, in which the coffin was being carried, through the streets of Rawalpindi.