ISLAMABAD, Pakistan — Police swung batons and fired tear gas at supporters of former Prime Minister Benazir Bhutto demonstrating near Pakistan's parliament Wednesday, deepening a political crisis triggered by the imposition of military rule.

Associated Press reporters saw hundreds of protesters pushing metal barricades into ranks of riot police blocking their path. Police beat several activists who broke through, and dragged at least three away from the scene.

State television said the parliament had endorsed President Gen. Pervez Musharraf's state of emergency declaration.

The demonstrators pulled back after several rounds of tear gas were fired toward them.

Bhutto had called on supporters to defy a ban on protesting the imposition of emergency rule, even as the government threatened to crush her demonstrations.

She also said more than 400 members of her Pakistan People's Party have been arrested.

Musharraf, who took power in a 1999 coup, suspended the constitution after declaring the state of emergency Saturday. He has since ousted independent-minded judges, put a stranglehold on the media and granted sweeping powers to authorities to crush dissent. Thousands of people have been rounded up and thrown in jail since then.

With the encouragement of the United States, Musharraf had been holding talks with Bhutto that were widely expected to lead to a power-sharing arrangement after parliamentary elections, which were originally slated for January.

Bhutto said Tuesday that Musharraf's resort to authoritarian measures was a "breach of trust" with her and that the talks were off. However, she also suggested that they could resume if circumstances change.

"I think we should all come down as strongly as we can for the restoration of democracy. And if General Musharraf wants to find a way out, well the ball is in his court," she said.

The United States and other foreign donors to Pakistan are pressing loudly for the elections to be held on time. They are also urging Musharraf to keep a promise to quit his post as army chief — the real source of his power.

"For elections to be credible, opposition political party leaders and their party workers must be released from jail or house arrest. The media must be free to report on events and share their opinions with the public," U.S. Ambassador Anne Patterson said after meeting the head of the election commission on Tuesday.

Musharraf says he suspended the constitution because the courts were hampering Pakistan's effort to fight extremism — for instance by ordering the release of suspects held without charge. But opponents accuse him of a mounting a last-ditch maneuver to stay in power.

In an op-ed piece published Wednesday in The New York Times, Bhutto urged the U.S. to tell Musharraf it expects internationally monitored elections to be held within 60 days.

"It is dangerous to stand up to a military dictatorship, but more dangerous not to," Bhutto wrote. "The moment has come for the Western democracies to show us in their actions, and not just in their rhetoric, which side they are on."

Bhutto invited other opposition parties to a meeting in Islamabad on Wednesday to discuss a joint strategy against the emergency. However, the party of Nawaz Sharif, the premier Musharraf deposed in a coup in 1999, snubbed the gathering.

Sharif urged the West on Wednesday to abandon Musharraf but also ruled out teaming up with Benazir Bhutto, another key opposition leader, unless she cut off talks with Musharraf.

Sharif told The Associated Press that Pakistan was heading deeper into chaos and his archenemy had outlived his usefulness in fighting terrorism.

"One man is holding the entire nation hostage for his personal interests," Sharif said.

"The political forces, the lawyers and civil community that believe in moderation and democracy, they are sidelined today. Who is going to get the benefit? It will be the radicals and extremists, they will thrive now," he said in a telephone interview from Saudi Arabia, where he was deported in September after attempting to return to Pakistan. "Mr Musharraf is a man who has outlived his utility in terms of fighting any battle against terror."

Sharif, whose government was ousted by Musharraf in a 1999 coup and has spent the last seven years in exile, said thousands of his party members had been rounded up in the past four days.

He urged the public to protest against Musharraf, and predicted that unless the state of emergency was reversed and Musharraf ousted, the country could be pitched toward "catastrophe."

"Even the ruling junta today does not know how to go get out of this situation they have got into," he said.

Musharraf purged the Supreme Court just as it was preparing to rule on the legality of his contested re-election as president last month. The court also has pressed for authorities to allow the return of Sharif from exile in Saudi Arabia.

On Wednesday, police pushed back about 80 lawyers who tried to gather near the main court complex in Rawalpindi, said Mohammed Khan Zaman, a member of the local lawyers' association.

In Islamabad, about 200 attorneys held a rally inside the district court, chanting "Go Musharraf, Go!" and "No Musharraf, No!"

Lawyers particularly are incensed by the ouster of Chief Justice Iftikhar Mohammed Chaudhry, an independent-minded judge whom Musharraf had tried unsuccessfully to fire earlier this year.

Chaudhry is under house arrest in Islamabad but managed on Tuesday to use a cell phone to urge lawyers to take to the streets.

"We should act upon this message and it will be decided once and for all if the army or the people will rule Pakistan," Zaman said.

Associated Press writers Munir Ahmad and Zarar Khan contributed to this report.