President Gen. Pervez Musharraf suspended Pakistan's constitution and deployed troops in the capital Saturday, declaring that rising Islamic extremism had forced him to take emergency measures. He also replaced the chief justice and blacked out the independent media that refused to support him.

Authorities began rounding up opposition politicians, cut phone lines in Islamabad and took all but state television off air, defying calls from Washington and other Western allies not to take authoritarian measures.

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On Sunday, police arrested Javed Hashmi, the acting president of exiled former Prime Minister Nawaz Sharif's party. Hashmi was arrested along with 10 aides when he stepped outside his house in the central city of Multan. Police also arrested six lawyers, including the secretary of the Multan High Court Bar Association.

The U.S. said it was disappointed and called for Musharraf to restore democracy. However, the Pentagon said the emergency declaration does not affect U.S. military support for Pakistan and its efforts in the war on terrorism. Britain said it was deeply concerned.

Musharraf's leadership is threatened by an increasingly defiant Supreme Court, the reemergence of political rival and former prime minister Benazir Bhutto and an Islamic movement that has spread to the capital. The Supreme Court was expected to rule soon on the validity of Musharraf's contentious re-election last month.

Attorney General Malik Mohammed Qayyum denied claims in the media and from Bhutto, that Musharraf had imposed martial law — direct rule by the army — without announcing it. He said this was not the case as the prime minister and parliament were still in place.

Analysts said the emergency measures may only postpone Musharraf's political demise.

In a televised address late Saturday night, Musharraf looked somber and composed, wearing a black tunic rather than his usual military fatigues. He said Pakistan was at a "dangerous" juncture.

"The extremism has even spread to Islamabad, and the extremists are taking the writ of the government in their own hands, and even worse they are imposing their obsolete ideas on moderates," he said.

Musharraf's order allows courts to function but suspends some fundamental rights guaranteed by the constitution, including freedom of speech. It also allows authorities to detain people without informing them of the charges.

He replaced chief justice Iftikhar Mohammed Chaudhry — who had emerged as the main check on his power. Musharraf's popularity plunged after he tried and failed to fire Chaudhry this spring, sparking popular protests against military rule.

Musharraf was overwhelmingly re-elected last month by the current parliament, dominated by his ruling party, but the vote was challenged. The Supreme Court was due to rule on whether he could run for president while still serving as army chief before his current term expires Nov. 15.

Musharraf criticized the court for failing to validate his re-election and for punishing government officers, including police. He said this had left the government system "semi-paralyzed."

His emergency order accused some judges of "working at cross purposes with the executive" and "weakening the government's resolve" to fight terrorism.

Musharraf claimed that the court had ordered 61 terrorists freed — an apparent reference a case that has been led by the now-deposed chief justice to press authorities over suspects held by intelligence agencies without charge.

Seven of the 17 Supreme Court judges immediately rejected the emergency, which suspended the current constitution. Paramilitary troops blocked entry to the Supreme Court building and erected road blocks and barred access to the official residences of lawmakers and judges. They later took the deposed chief justice and other judges away in a convoy, witnesses said.

Musharraf said he hoped democracy would be restored following parliamentary elections.

"But, in my eyes, I say with sorrow that some elements are creating hurdles in the way of democracy," said Musharraf. "I think this chaos is being created for personal interests and to harm Pakistan."

Rick Barton, a Pakistan expert at the Washington-based Center for International and Strategic Studies, said Musharraf's move would likely only postpone his political downfall.

"He's obviously not very popular, and it's not going to increase his popularity," Barton said. "Unless he's develops a new line or is able to be more effective with his old line, he seems to be just buying time, an inevitable delay to his demise."

The order drew swift complaints from the United States and Britain — Musharraf's main Western allies. Secretary of State Condoleezza Rice urged restraint on all sides and a return to democracy.

The United States "does not support extraconstitutional measures," Rice said from Turkey, where she was participating in a conference with Iraq's neighbors.

Pentagon spokesman Geoff Morrell, however, said the emergency declaration "does not impact our military support of Pakistan" or its efforts in the war on terror.

Musharraf, who seized power in a 1999 coup and has been a close ally of the United States since the Sept. 11, 2001, attacks, has struggled to contain Taliban and Al Qaeda-linked militants who have gained control of large tracts of the volatile northwest near Afghanistan. Hundreds have died in fighting in recent weeks.

The violence has reached major cities despite substantial financial backing from the United States for the war on terrorism.

Bhutto, a longtime rival of Musharraf who recently returned from eight years of exile, is seen by many supporters as key to a possible return to democracy. On Saturday, she flew back to the southern city of Karachi from Dubai where she was visiting family. She had traveled abroad in the wake of an Oct. 18 suicide attack that narrowly missed her but killed 145 others.

She declared the emergency was the "blackest day" in Pakistan's history.

After her arrival at Karachi's Airport, Bhutto said she did not believe there would be fair elections as long as emergency rule remained in place.

"I agree with him that we are facing a political crisis, but I believe the problem is dictatorship, I don't believe the solution is dictatorship," she told Sky News television by telephone.

1n Karachi, about 100 police and paramilitary troops were deployed outside Bhutto's house, apparently as a protective cordon, witnesses said. A bomb disposal squad also searched the house before she arrived.

Sharif, deported in September as he tried to return from exile, urged Pakistanis to rise against Musharraf.

The president of the Supreme Court Bar Association, Aitzaz Ahsan was arrested, private Geo TV reported. Ahsan was a lawyer for Chaudhry in the case that led to his reinstatement in July.

Another opposition party leader, Imran Khan, was put under house arrest and police were rounding up opposition activists and lawyers across Punjab province.

Asma Jehagir, chairman of the independent Human Rights Commission of Pakistan who has acted as a rapporteur for the United Nations, told The Associated Press on Sunday that she had been put under house arrest in Lahore.

By early Sunday, cell phone service appeared to have been restored, but landlines were still dead. Transmissions by TV networks remained off the air in major cities other than state-controlled Pakistan TV.

Musharraf said some independent TV channels had contributed to the uncertainty in the country.

He also issued two ordinances toughening media laws, including a ban on live television broadcasts of "incidents of violence and conflict." Also, TV operators who "ridicule" the president, armed forces, or executive, legislative or judicial organs of the state can be punished with three years in jail.

It was not clear whether U.S. officials had advance knowledge of Saturday's action.

Rice said that to her knowledge, U.S. officials had yet to hear directly from Musharraf after his declaration. She said she last spoke with Musharraf a couple days ago but that other U.S. officials had made the American position clear to him more recently.

Crucial parliamentary elections meant to restore civilian rule are due by January and Musharraf did not say when they would be held.

Musharraf said there would be no change in the government and its top offices, and parliament — set to dissolve by Nov. 15 — would complete its term.