Pakistan put off its general election by 6 weeks to February 18 on Wednesday following the assassination of Benazir Bhutto, over the objections of the main opposition parties which fear a delay will work against them.

The killing of the charismatic opposition leader has fuelled doubts about stability and the transition to democratic rule in nuclear-armed Pakistan, a key ally in the U.S. anti-terrorism drive.

"In all the four provinces, for some days this election process came to a complete halt," Chief Election Commissioner Qazi Mohammad Farooq told a news conference.

"Polling will now be held on February 18 instead of January 8."

President Pervez Musharraf, in a televised address to the nation, said army and paramilitary troops would deal forcefully with any renewed violence and appealed for national reconciliation leading to free and fair elections.

"The army and the rangers will be fully deployed to ensure law and order across the country and for holding elections peacefully," Musharraf said. Rangers are a paramilitary force.

"This is time for national reconciliation and not confrontation," he said. Bhutto's mission was the promotion of democracy and the struggle against terrorism: "I assure you I have the same mission," he added.

Farooq said election offices in 11 districts of Sindh, Bhutto's home province, were burned down in the disturbances, destroying transparent ballot boxes, voter screens, voters' lists and other election materials.

Supporters of Bhutto's Pakistan People's Party (PPP) and the other main opposition party, led by former prime minister Nawaz Sharif, had wanted the election to go ahead as planned, fearing a delay would work to Musharraf's advantage.

"We condemn the postponement of elections, but even then we will go into the polls," Bhutto's husband, Asif Ali Zardari, told a news conference at her home in Naudero town.

SYMPATHY VOTE

Bhutto's party would expect to reap a considerable sympathy vote following her assassination in a gun and bomb attack as she left a rally in Rawalpindi on Thursday.

Nearly 60 people were killed in the ensuing violence and analysts said a postponement could lead to renewed rioting. Tension remains high and markets are gripped by fears of capital flight if security worsens.

In his speech, Musharraf said he was certain allies of the al Qaeda militant group were behind Bhutto's killing.

Al Qaeda-linked militants are involved in all attacks in Pakistan, including recent attacks on security forces and politicians, he said. "I want to say it with certainty, that these people martyred ... Benazir Bhutto," he added.

Bhutto was seen as a U.S. ally and was one of the strongest moderate voices trying to wrest back influence in the Islamic world from men like Osama bin Laden.

Her killing has spawned a host of conspiracy theories, some Pakistanis believing she was killed by rogue elements in the establishment.

Musharraf said he had asked British police for help in investigating the assassination and Scotland Yard said a group of counter-terrorism officers would go to Pakistan shortly.

Sharif's Pakistan Muslim League (Nawaz) said opposition parties should unite and demand that Musharraf and the election commission step down.

"General Musharraf has failed to ensure law and order and the election commission has failed to hold elections on schedule," said spokesman Ahsan Iqbal. "... both must resign and we should have a neutral national unity government and an independent election commission."

Echoing that view, the International Crisis Group said in a briefing "If Pakistan is to be stable in the wake of Benazir Bhutto's murder, President Musharraf must resign and a quick transition follow to a democratically elected civilian government."

"Unless he steps down, tensions will worsen and the international community could face the nightmare of a nuclear-armed, Muslim country descending into civil war from which extremists would stand to gain," the think tank added.

Pakistani shares slid 2.3 percent, taking the fall in the main share index since Bhutto's death to nearly 10 percent.

"The market was expecting a delay ... The issue now is what reaction the political parties will have and that might affect the market," said Ahsan Mehanti, chief executive of Shehzad Chamdia Securities, after the announcement of the poll delay.