ISLAMABAD, Pakistan — Pakistan elections will be delayed by one month following the turmoil sparked by Benazir Bhutto’s assassination, despite opposition threats of street protests unless the crucial vote is held January 8 as originally planned, a top official said yesterday.

A senior Election Commission official told the Associated Press that the commission has agreed on a new date. He indicated it would not be before the second week of February, but he refused to disclose the exact schedule before the formal announcement today.

The opposition is likely to accuse authorities of postponing the polls to help the ruling party, which is allied to President Musharraf. Many believe Bhutto’s party could get a sympathy boost if the vote takes place on time. Bhutto had accused elements in the ruling party of plotting to kill her, a charge that it vehemently denies. The killing of Bhutto, a former prime minister, triggered three days of nationwide riots that killed 58 people and caused tens of millions of dollars in damage. Bhutto’s home province of Sindh was especially hard-hit and the army was called on the streets. Ten election offices were burned.

“We need at least one month to make arrangements to hold free and fair elections after the damage caused to our offices in the Sindh province,” the official said, adding that the commission had already consulted the main political parties about the delay. He spoke on condition of anonymity because he was not authorized to disclose the decision.

In addition to logistical problems arising from the destruction caused by the rioting, he said the caretaker governments of all four provinces of Pakistan had suggested the vote not be held during the holy month of Muharram between January 10 and February 8, because they could not guarantee security. Sectarian violence often breaks out between Pakistan’s Shiite and Sunni Muslims.

The polls are seen as crucial to restoring democracy after eight years of military rule and following a six-week state of emergency that Mr. Musharraf declared in November.

Opposition groups have demanded the elections proceed on time, and Nawaz Sharif, leader of another opposition party, threatened street protests if they were postponed. Bhutto’s party, certain to win sympathy votes in a quick election, accused Mr. Musharraf of wanting a delay to allow anger over her death to evaporate.

“There have been elections in conflict zones such as Iraq and Afghanistan so I find it difficult to understand why this election cannot be held on time,” Sherry Rehman, a spokeswoman for Bhutto’s party, told Dawn News TV.

Britain and America were also eager for the vote to take place as scheduled but have indicated they would accept a slight delay.

Meanwhile, a top aide of Bhutto said that on the day she was killed, the opposition leader was planning to give two American lawmakers a 160-page dossier accusing the government of rigging the elections.

Bhutto was killed Thursday in a shooting and bombing attack on her vehicle as she left a campaign rally. She had been scheduled to meet hours later with Senator Specter of Pennsylvania and Rep. Patrick Kennedy of Rhode Island.