ISLAMABAD, Pakistan -- President Pervez Musharraf expressed determination yesterday to restore law and order after the country was racked by a third day of riots and looting that have killed nearly 50 people since the assassination of Benazir Bhutto.
Officials said at least 44 people have been killed in unrest that broke out Thursday night after the former prime minister was killed as she left a campaign rally.
Much of the unrest has been concentrated in and around Karachi, the southern port city that was Bhutto's home base. It has a long history of political violence and is a stronghold of a pro-Musharraf party.
Among the recent casualties was a young man shot to death in Karachi while wearing a tunic made from the flag of Bhutto's party. A gunbattle in the streets of the city killed three other people.
Clashes also broke out yesterday in Rawalpindi, the city where Bhutto was killed. After leaving a memorial service, some supporters threw stones at police, who responded with tear gas.
Other parts of the country, including the capital, Islamabad, remained mostly calm.
Also yesterday, Pakistan rejected foreign help in investigating Bhutto's assassination, though U.S. officials said Pakistani officials have quietly begun consulting with other nations about the conduct of their investigation
"The Pakistan government is discussing with other governments as to how best the investigation can be handled," one senior U.S. official said, speaking on condition of anonymity, because no agreement had yet come from the discussions.
With the United States, the official said, the discussions "are about what we can offer and what the Pakistanis want. Having some help to make sure international questions are answered is definitely an option."
There was no immediate confirmation from Pakistani officials.
The Islamic militant group blamed by officials for the attack that killed Bhutto denied any links to the killing yesterday, and Bhutto's aides accused the government of a cover-up.
President Pervez Musharraf ordered his security chiefs to quell rioting.
Paramilitary troops in the most volatile areas have been given permission to use deadly force against rioters.
"Criminals should stop their despicable activities, otherwise they will have to face serious consequences," Interior Ministry spokesman Javed Iqbal Cheema said.
Property damage was estimated in the tens of millions of dollars.
The country has been in a state of virtual shutdown since Bhutto was killed, but that appeared in part because of violence and in part because of the three official days of mourning that Musharraf declared.
Officials indicated that the violence might affect a decision on whether to go ahead with parliamentary elections scheduled for Jan. 8. The Election Commission was to meet tomorrow to discuss whether the vote should be postponed.
Laura King writes for the Los Angeles Times. The Associated Press contributed to this article.