ISLAMABAD, Pakistan (AP) -- Police rounded up hundreds of opposition leaders and rights activists Sunday after Pakistan's military ruler suspended the constitution, ousted the top judge and deployed troops to fight what he called rising Islamic extremism.

Increasingly concerned by the unfolding crisis, the Bush administration said Sunday that American aid to Pakistan would be reviewed. The U.S. has provided about $11 billion to Pakistan since 2001, when Pakistan's president, Gen. Pervez Musharraf, allied with the United States after the Sept. 11 attacks.
""Some of the aid that goes to Pakistan is directly related to the counterterrorism mission,"" Secretary of State Condoleezza Rice told reporters traveling with her. ""We just have to review the situation. But I would be very surprised if anyone wants the president to set aside or ignore"" the responsibility to national security that can come through such cooperation, she said.
In the lawless Afghan border region, militants freed 211 Pakistani soldiers captured two months ago, the army's top spokesman said.
Musharraf, a 1999 coup leader who had promised to relinquish his army post and become a civilian president this year, declared a state of emergency Saturday night, dashing hopes of a smooth transition to democracy for the nuclear-armed nation.
Musharraf's leadership is threatened by the reemergence of political rival and former Prime Minister Benazir Bhutto, an increasingly defiant Supreme Court set to rule on the validity of his recent presidential election win, and an Islamic militant movement that has spread from border regions to the capital.
South Waziristan, the tribal border region where the government is struggling to assert control, has seen a surge in violence, including the capture of the soldiers two months ago. The group was freed Sunday through the efforts of a jirga or a tribal council of elders in South Waziristan, said Maj. Gen. Waheed Arshad.
Crucial parliamentary elections expected in January could now be delayed by up to a year, Prime Minister Shaukat Aziz said, stressing that such a decision had not yet been reached. He said the extraordinary measures would be in place as long as necessary.
Aziz said up to 500 opposition activists had been arrested nationwide in the last 24 hours, about 45 of them in the capital, Islamabad.
Among them were Javed Hashmi, the acting president of the party of former Prime Minister Nawaz Sharif; cricket star-turned politician, Imran Khan; Asma Jehangir, chairman of the independent Human Rights Commission of Pakistan; and Hamid Gul, former chief of the main intelligence agency and a staunch critic of Musharraf's support for the U.S.
Some 200 armed police stormed the rights commission office in Lahore on Sunday and arrested about 50 activists, said Mehboob Ahmed Khan, a legal officer for the body.
""They dragged us out, including the women,"" he said from the police station in the eastern city. ""It's inhuman, undemocratic and a violation of human rights to enter a room and arrest people gathering peacefully there.""