Your Views
Benazir Bhutto has been killed in a suicide attack. What next for Pakistan?
The PPP said it would observe a 40-day period of mourning while Nawaz Sharif, another opposition leader and former prime minister, has called for a nationwide strike on Friday.
Killing condemned
Pervez Musharraf, the Pakistan president, condemned the killing and announced three days of mourning.
The life and times of Benazir
Seventeen people, including three policemen, had been killed in violent protests so far, police and a provincial government minister said on Friday.
A Reuters reporter travelling through Sindh said he had seen hundreds of burnt-out vehicles, and people were coming out on Friday morning and setting fire to more and trying to block roads.
Unidentified assailants shot dead a policeman in a neighbourhood of Karachi.
"Unknown people gunned down a police constable in Lyari this morning," said Fayyaz Khan, a senior police official.