The house arrest order against Pakistani opposition leader Benazir Bhutto has been lifted. Earlier Friday, the order was used to stop the former prime minister from attending a rally of her supporters.

"The detention order has been withdrawn," Acting Deputy Commissioner of Islamabad Aamir Ali Ahmed said.

The crackdown has thrown into doubt an alliance between Bhutto and President Gen. Pervez Musharraf, both of whom are considered pro-U.S. and oppose Islamic extremism.

Earlier, police used an armoured vehicle to twice block Bhutto's white Land Cruiser from leaving her home in Islamabad. They also uncoiled barbed wire in front of her residence.

The former prime minister was scheduled to speak at a rally in nearby Rawalpindi despite a government-imposed ban on public gatherings.

A top Interior Ministry official, Kamal Shah, said Friday that the "detention order" had been issued for Bhutto preventing her from leaving her home.

"She dealt with it in a very strong manner by getting into her vehicle, driving through police lines, making her way to the front of the barricade where she was able to speak to the media -- very important in this case -- and to those few supporters who were able to get to the house," CTV's Paul Workman reported from Islamabad.

During her second attempt to leave, Bhutto addressed police through a loudspeaker: "Give me way. Do not raise hands on women. You are Muslims. This is un-Islamic. We are peaceful."

Bhutto claimed 5,000 members of her Pakistan People's Party (PPP) have been detained in the last three days.

In Rawalpindi, police used tear gas and batons to clear out about 200 Bhutto supporters. Dozens were arrested and a second, smaller clash ensued between protesters and police.

The mayor of Rawalpindi said there was a "credible report" that six or seven suicide bombers were preparing to attack the rally.

"That was one of the reasons why they didn't want Benazir Bhutto to go ahead with her planned rally," said Workman.

When Bhutto returned to Pakistan on Oct. 18, attackers detonated two bombs, killing more than 140 people.

On Friday, Foreign Affairs Minister Maxime Bernier said Canada will call on Commonwealth ministers next week to take a hard line on Pakistan. 

The White House also urged Pakistan to grant Bhutto and other political opponents the freedom to move about freely.

"We remain concerned about the continued state of emergency and curtailment of basic freedoms, and urge Pakistani authorities to quickly return to constitutional order and democratic norms," Gordon Johndroe, a spokesman for the U.S. National Security Council said in a statement.

A police presence remained at Bhutto's home overnight, prompting a senior official leaving a midnight meeting to say she would try to leave Saturday morning.

"We'll see tomorrow," said Makhdoom Shah Qureshi, a senior official from Bhutto's Pakistan People's Party. "You can see for yourself the barriers are still up, the police are still here."

Musharraf's crackdown

Bhutto's return to Pakistan after eight years of self-imposed exile had been preceded by talks with Musharraf. The two were expected to reach some type of power-sharing arrangement after the scheduled parliamentary elections in January.

But last week, Musharraf -- who took power in a 1999 military coup -- suspended the constitution and assumed emergency powers.

He said he was forced to declare a state of emergency because Islamic extremists were threatening the government's authority.

But since the declaration, the government has detained thousands of activists, purged the Supreme Court and put a stranglehold on the electronic media.

Most of the thousands arrested have been moderates, including lawyers and activists.

Critics claim Musharraf is simply trying to keep a grip on power.

On Friday, Bhutto called on Musharraf to revive the constitution and respect the judiciary. She also called on him to retire as chief of army staff by Nov. 15.

The country's Supreme Court was supposed to rule in the coming days on whether Musharraf was legally able to run as a presidential candidate in last month's elections, considering he still heads the army.

Musharraf reaffirmed Thursday that he would quit his role as chief of army staff but only once the Supreme Court validated his recent election win as president.

Musharraf also said parliamentary elections would proceed by mid-February -- a month later than originally planned.

"There is now a huge amount of international pressure against him to lift the emergency law, to quit as the head of the army and to call elections," said Workman.

Meanwhile, a bomb at the home of a government minister in Peshawar killed at least four Friday.

Police say the suicide bomb attack occurred at the residence of the minister for political affairs, Amir Muqam. The minister was not injured.

Workman said Bhutto has called a long march from Lahore to Islamabad for next week.

With files from The Associated Press