The assassination of Benazir Bhutto has thrown into doubt whether Pakistan can hold an election in 10 days' time that was meant to complete a transition to civilian rule in the nuclear-armed US ally.
Opposition leader Bhutto was killed in a suicide attack on Thursday as she left an election rally in the city of Rawalpindi. The Government has blamed Al-Qaeda.
The United States and other Western allies have urged President Pervez Musharraf to press ahead with polls they hope will bring stability to a country emerging from eight years of military rule while facing mounting violence from Islamist militants allied to Al-Qaeda.
Prospects for a smooth poll look bleak with the head of the country's biggest political party dead and the other main opposition party announcing an election boycott in response to her murder.
Bhutto had hoped to win the January 8 vote, though most analysts had expected a three-way split between her, former prime minister Nawaz Sharif and a party that backs President Pervez Musharraf.
Caretaker Prime Minister Mohammadmian Soomro is consulting parties about the vote but said the schedule remained in place.
But with Bhutto's supporters rioting in parts of the country and suicide bombers on the prowl, some analysts expect only more bloodshed if the Government pushes ahead as planned.
"It's very, very difficult to hold elections unless tempers are cooled off and it's not possible in such a short time," said retired general and political analyst Talat Masood. The Election Commission said 11 of its offices in Sindh had been torched and voting material including electoral rolls destroyed. Security in two northwestern regions also raised doubts about voting there, it said.
It would hold an emergency meeting tomorrow, it said.
Maulana Fazl-ur-Rehman, the leader of Jamiat-e-ulema-e-Islam, an Islamist party strong in the volatile North West Frontier Province, said it was hard to see how people could vote safely. "The situation in the country is very critical. Especially in Sindh province," Rehman told Reuters.
Cricketer-turned-politician Imran Khan, whose small party was already planning to boycott the poll, also questioned whether it was feasible to hold an election. "It's not a question of fair, it's just not possible," he told BBC radio. "You've seen the scenes of people rioting. There is so much tension on the street, how are they going to have polling booths manned?"
Hours after Bhutto's death, Sharif, who Musharraf ousted in a 1999 coup, said his party would not take part. Barred from contesting the poll, Sharif had earlier only decided to let his party participate after Bhutto said she would not join a boycott.
Leaders of Bhutto's traumatised party are due to meet today and are expected to decide whether to fight the election. The PPP could expect a sympathy vote if it did.
A boycott by both main opposition parties would render the vote virtually meaningless.
Sharif travelled to the south yesterday to meet Bhutto's husband, Asif Ali Zardari, who could take over as leader of her Pakistan People's Party, and other party leaders, to urge them to join his boycott.
"Our decision was to express solidarity with the People's Party and we stand by it," Sharif told reporters in Lahore before setting off. "I'm going there and will try to convince them."
Musharraf, needing support from the next parliament, will have to weigh the risks of holding polls on time or seeking a postponement.
Bhutto's death has inflamed anger against the former army chief, whose popularity had already slumped after he clashed with the judiciary this year and imposed emergency rule for six weeks from early November.
The party that backs him, the Pakistan Muslim League (Q), could gain from a Sharif party boycott, especially in the key province of Punjab.