ISLAMABAD — Police fired tear gas and clubbed thousands of lawyers protesting President Musharraf’s decision to impose emergency rule, as Western allies threatened to review aid to the troubled Muslim nation. Opposition groups put the number of arrests at 3,500, although the government reported half that.

General Musharraf, who took power in a 1999 coup and is also head of Pakistan’s army, suspended the constitution on Saturday ahead of a Supreme Court ruling on whether his recent re-election as president was legal. He ousted independent-minded judges, put a stranglehold on independent media and granted sweeping powers to authorities to crush dissent.

Though public anger was mounting in the nation of 160 million people, which has been under military rule for much of its 60-year history, demonstrations so far have been limited largely to activists, rights workers, and lawyers. All have been quickly and sometimes brutally stamped out.

A spokesman for the party of a former prime minister, Nawaz Sharif, said today that authorities had rounded up around 2,300 of its supporters. Other opposition parties, human rights groups, and lawyers said another 1,200 had been arrested.

Secretary of State Rice urged General Musharraf to follow through on past promises to “take off his uniform” and restore civilian rule.

“I want to be very clear. We believe that the best path for Pakistan is to quickly return to a constitutional path and then to hold elections,” she said at a news conference in Ramallah, West Bank.

Independent TV news networks remained off the air today. Police raided a printing press in Karachi belonging to Pakistan’s largest media group, blocking publication of its Urdu-language evening newspaper, Awam, or People, a Jang Group managing director, Shahrukh Hassan, said from the scene.

Mr. Hassan said printing for today’s evening paper was stopped, but negotiations were continuing over whether the press could reopen for the group’s Tuesday editions, including Pakistan’s largest-circulation daily, Jang.

America has said it is reviewing its aid to Pakistan, a key ally in fighting Al Qaeda and Taliban militants that has received billions in assistance since General Musharraf threw the Islamic nation’s support behind the American-led war on terror after the September 11, 2001, attacks.

Today, the American Embassy said that an American-Pakistan defense cooperation meeting planned for this week had been postponed amid the current uncertainty in Pakistan.

Western nations had urged General Musharraf against taking authoritarian measures, but the military leader said it was needed to counter a growing militant Islamic movement and a court system that hindered his powers.

General Musharraf briefed foreign ambassadors today, saying the “superior judiciary paralyzed various organs of the state and created impediments in the fight against terrorism,” state-run Associated Press of Pakistan reported.

General Musharraf, however, reiterated that he would complete the transition to democracy. His government said yesterday parliamentary elections could be delayed up to a year.

Since late Saturday, between 1,500 and 1,800 people have been detained nationwide, an Interior Ministry official said on condition of anonymity because he was not authorized to speak to the media. They include opposition leaders, lawyers, and human rights activists who might mobilize protests.