ISLAMABAD - A key opposition group vowed Sunday to try to undo amendments President Pervez Musharraf made to the constitution before lifting emergency rule, changes critics say will keep a tight lid on dissent.

President Pervez Musharraf lifted a six-week-old state of emergency Saturday, telling a skeptical nation the crackdown was to save Pakistan from a conspiracy rather than ensure his own political survival.

But Musharraf entrenched limits he imposed under the emergency, including strict curbs on press freedom and the replacement of independent-minded judges with jurists friendlier to the U.S.-backed leader. Opponents have said the changes set the stage for parliamentary elections next month to be rigged, and have threatened to hold mass demonstrations.

The Pakistan Muslim League-N party, led by former Prime Minister Nawaz Sharif, will seek to use the new legislature to reverse the amendments, said party chairman Raja Zafarul Haq.

Haq said the state of emergency "will leave a bitter legacy" long after Musharraf leaves office. He insisted the Jan. 8 elections will be rigged, saying Musharraf used the emergency to stack the Supreme Court with hand-picked judges.

Several leading newspapers lauded the end of emergency rule but criticized Musharraf for amending the constitution without parliamentary approval. "A blow has been delivered to the very concept of parliamentary sovereignty," the daily Dawn said in an editorial.

Musharraf on Friday removed a condition from the constitution stating that civil servants -- including army officers -- had to wait two years after their retirement before running for elected office, Attorney General Malik Mohammed Qayyum said.

Musharraf stepped down as army chief only last month. Removing the provision in question eliminated one of the grounds used to challenge his October re-election by a Parliament stacked with his supporters.

Qayyum said other changes sealed the retirement of purged Supreme Court judges. Their replacements swiftly approved Musharraf's re-election.

Musharraf said in a nationally televised speech Saturday the emergency helped slow the spread of Islamic militancy.

Al-Qaida and Taliban-linked militants are believed to be hiding along Pakistan's border with Afghanistan.

On Sunday, a roadside bomb explosion seriously wounded three paramilitary troops in a tribal area in northwestern Pakistan, an intelligence official said on condition of anonymity because he was unauthorized to speak to the media.

The army said it captured seven suspected militants in Swat, another restive region where the military has said it routed fighters loyal to a pro-Taliban cleric.

Musharraf said unnamed conspirators had hatched a plot with members of the judiciary to derail the country's transition to democracy, and he warned political parties to avoid stirring up trouble.

He vowed the Jan. 8 balloting "will be absolutely fair and transparent."

The response was muted from the U.S., which has walked a fine line between criticizing the democratic backsliding by Musharraf and supporting a key ally against Islamic militancy.

"It's a good step for the Pakistani people," said White House spokeswoman Jeanie Mamo.

Former Prime Minister Benazir Bhutto, another leading government opponent, dismissed Musharraf's claim that opposition parties were raising fraud allegations in anticipation of losing the elections. She said the election commission and many local officials involved in the balloting have partisan ties to the ruling party and are working to foster a hung Parliament that would help the current coalition remain in power.

"They have planted chosen presiding officers, police officials and persons from the administrative machinery in marked constituencies, and intelligence agencies are constantly engaged in trying to steal the people's mandate," Bhutto told reporters during a campaign stop in Quetta.