President Pervez Musharraf told British forensic experts Tuesday they would have a free hand in investigating the circumstances surrounding the assassination of opposition leader Benazir Bhutto, a government official said.

The promise appeared to be a softening of the government's position on the probe. Last week, Musharraf told reporters the investigators would not be allowed to go on a "wild goose chase" and investigate claims the government was behind Bhutto's killing in a Dec. 27 shooting and bombing attack.

"The president assured (the investigators) of his full support and said that they were totally free to conduct their probe, and no one will interfere in their affairs," Interior Ministry spokesman Javed Iqbal Cheema said.

The government blamed the attack on Islamic militants and initially said Bhutto was killed when the force of the blast slammed her head into a lever on the sunroof of her car. The opposition blamed elements of the ruling party and said she was killed by gunshot wounds.

Bhutto's killing plunged Pakistan, a key U.S. ally in the war on terror, even deeper into political crisis at a time when it is battling militants linked to al-Qaida and the Taliban movement. Elections originally set for Jan. 8 have since been pushed back to Feb. 18 because of unrest after the slaying, despite demands from Bhutto's and other opposition parties that they be held as scheduled.

Amid growing calls for an international probe into her death, Musharraf invited a six-member team from Scotland Yard's antiterror division to assist local investigators.

Upon their arrival last week, the British experts visited the site of the attack in the garrison city of Rawalpindi to take photographs and record video and spoke with local security officers. They have made no comment since their arrival.

"The forensic experts and analysts from Scotland Yard are independently and freely conducting their investigation. They are helping Pakistan to determine the motives behind the attack and to help us know the exact cause of Benazir Bhutto's death," Cheema said. "Whenever the team from Scotland Yard reaches any conclusion, we will share it with the people."

The team's meeting with Musharraf came a day after Bhutto's supporters called for the formation of a U.N. committee with a broad mandate to investigate Bhutto's assassination.

"This was not just a Pakistani issue, it is an issue that will reverberate not just in the region, it will reverberate in the world," Sherry Rehman, spokeswoman for the Pakistan People's Party, said Monday.

Rehman said the government had failed to properly investigate an Oct. 18 suicide bombing that targeted Bhutto during her homecoming parade in the city of Karachi and killed about 150 people. That failure led to the successful attack on Bhutto two months later, she told reporters.

Rehman demanded the U.N. Security Council authorize an investigation into Bhutto's killing and the events leading to it. She also reiterated accusations, denied by the government, that Bhutto was not given proper security.

Rehman also railed against the government's decision to postpone the polls in the wake of days of rioting that followed Bhutto's killing, accusing it of using the delay to rig the vote.

"The People's Party condemns the delay in the election and will not tolerate any further move to delay it or hijack this election," she said.

Also Tuesday, Pakistani intelligence agents arrested a suspected al-Qaida-linked militant and six of his associates in connection with an attack on an air force bus in November that killed eight people and wounded about 40 others, a security official said.

The suspect, identified as Ahsanul Haq, a retired army major, was caught in the eastern city of Lahore last month following the Nov. 1 attack in Sargodha, about 125 miles south of the capital, Islamabad, the official said.

Haq told security forces the name of the bomber, who belonged to an outlawed militant group, the security official said on condition of anonymity because he was not authorized to speak to the media.