The Election Commission of Pakistan announced Wednesday that crucial elections meant to usher in a return of civilian rule would be delayed for six weeks following the assassination of opposition leader Benazir Bhutto.

"The polling will now be held on February 18, 2008," Qazi Mohammed Farooq, the chief election commissioner, told a packed press conference.

Pakistani President Pervez Musharraf was scheduled to address the nation at 8 pm Wednesday about the polls, which had been scheduled for next Tuesday.

Farooq said extensive damage to election offices, ballot papers, voter rolls and other materials in more than a dozen districts in the southern province of Sindh, Bhutto's stronghold, following her slaying in a gun-suicide attack last Thursday made it impossible to hold them on time.

He also said the start of the month-long Muslim observance of Moharram around January 10 forced the commission to push the polls back further.

"Daily life across the country was affected by the disturbances - the election process was also affected," Farooq said. "In some parts of the country, the process was completely halted."

The country's main opposition parties, Bhutto's Pakistan People's Party and former prime minister Nawaz Sharif's Pakistan Muslim League-Nawaz (PML-N), had demanded that the polls be held as scheduled.

Ahsan Iqbal, a PML-N, told DawnNews TV, that the embattled Musharraf should resign for failing to hold the polls on time, and that a "national unity government" should be appointed to organize new elections to ensure they are fair.

Analysts say the opposition parties likely think they could sweep the elections if they were held on schedule, riding a wave of sympathy for Bhutto and massive dissatisfaction with Musharraf and his political backers, the ruling Pakistan Muslim League-Quaid (PML- Q).

PPP officials have publicly accused rogue elements with Musharraf's government of assassinating Bhutto, who was drawing huge crowds after returning from self-exile to campaign for an unprecedented third term as prime minister. They have demanded in United Nations inquiry into her death similar to one done following the assassination of former Lebanese prime minister Rafiq Hariri.

Musharraf's government had resisted the idea of a UN investigation into Bhutto's slaying, but given growing public skepticism with official government claims that the attack was carried out by Taliban fighters with ties to al-Qaeda, a Foreign Ministry spokesman said Wednesday that Pakistan would be open to international assistance.

The Bush administration, Musharraf's key foreign supporter, had been pushing for elections to be held on time as part of its strategy to help usher in the return of a popular civilian government following more than eight years of military rule under Musharraf, who just retired as chief of the army.

But US officials indicated in recent days that they would not object to a slight delay. The Bush administration is increasingly alarmed at growing Islamic militancy along Pakistan's western border with Afghanistan, where Taliban and al-Qaeda militants have regrouped and launched more than 200 suicide attacks in both countries.

The Bush administration had helped broker Bhutto's return home from self-exile to form a partnership with Musharraf to fight Islamic extremism and promote democracy in the nuclear-armed nation.