LAHORE, Pakistan – Exiled former Prime Minister Nawaz Sharif returned home to a hero’s welcome Sunday and called on President Gen. Pervez Musharraf to end emergency rule before elections, a fresh challenge to the U.S.-backed leader.

“These [emergency] conditions are not conducive to free and fair elections,” Sharif told reporters at the airport after arriving from Saudi Arabia. “I think the constitution of Pakistan should be restored, and there should be rule of law.”

Sharif, the head of one of the country’s main opposition parties, said he had not negotiated his return with Musharraf, who overthrew him in a 1999 coup. Musharraf expelled Sharif when he first tried come back to Pakistan this year.

“My return is not the result of any deal,” Sharif told reporters. “My life and death are for Pakistan.”

Thousands of frenzied supporters pushed past police barricades into the airport in this eastern city, carrying Sharif and his brother on their shoulders and cheering wildly as Sharif stood among them on a raised platform. An armored car carrying Sharif left the airport on a procession toward a shrine in the center of the city, surrounded by screaming supporters.

Musharraf has grown increasingly unpopular since he declared a state of emergency on Nov. 3, locking up thousands of opponents, purging the Supreme Court and muzzling the media.

If Sharif and other opposition parties refuse to take part in parliamentary elections slated for January, it would undermine Musharraf’s claim to be taking the country back toward democracy. Equally tricky for Musharraf would be an alliance between Sharif and another recently returned prime minister, Benazir Bhutto.

“If they come to us with a proposal of any electoral alliance, we will consider this positively,” Bhutto said aboard a flight from Karachi to her hometown of Larkana, in southern Pakistan. “I welcome him home.”

The presidential spokesman was not available Sunday for comment on Sharif’s return.

However, the pro-Musharraf ruling party, which broke away from Sharif’s group after the coup, is already wooing him as a potential ally.

Ruling party spokesman Tariq Azim urged the Sharif camp to “forget the old egos and start with a clean slate.”

The scene at Lahore airport was eerily reminiscent of the early jubilation that greeted Bhutto when she came back to her home city of Karachi in October, but the number of supporters was far lower. Bhutto’s return was greeted by a massive suicide bomb which killed about 150 people in a procession through the streets.

In a reminder that Pakistan remains under emergency rule, security forces had rounded up some Sharif activists and attempted to seal off the airport.

But the supporters who found their way through tight security swarmed into the terminal building waving the green flag of his party and shouting slogans including “Prime Minister Nawaz Sharif!” and “Go, Musharraf, go!”

Police lifted batons to drive them back from the arrival area, but had no space to swing them amid the dancing, jubilant crowds.

Television footage showed Sharif, dressed in his trademark white shirt and a dark waistcoat, on an airport stairwell next to his brother, also a politician, and surrounded by security officials, waving to the cameras.

Tight security that had surrounded Sharif after his plane touched down appeared to melt away amid the chaos.

Both Bhutto and Sharif have been seeking to return to power after the parliamentary elections. But the ballot, which the West hopes will produce a moderate government able to stand up to Islamic extremism, has been thrown into confusion by Musharraf’s seizure of emergency powers.

Major opposition parties – including Bhutto’s Pakistan People’s Party – have been lining up to take part in the elections with preliminary steps such as filing nomination papers.

Bhutto, a more liberal and openly pro-U.S. politician than Sharif, filed her papers to contest the election on Sunday in Karachi. She says her party could still pull out if Musharraf doesn’t ensure the vote is fair.

Sharif indicated his party, the Pakistan Muslim League-N, would demand a restoration of constitutional rule before it took part in the vote, but that any decision on whether to boycott would be taken in conjunction with other groups.

Sharif has been angling for a return ever since Musharraf overthrew him and gave the jailed politician a choice: accept 10 years of exile or face life in prison on charges including hijacking and terrorism. The charges stemmed from Sharif’s desperate attempts to turn away a packed civilian plane carrying Musharraf – then the army chief – back from a trip abroad.

As the Pakistan International Airways plane ran low on fuel, Musharraf used the cockpit radio to contact his senior commanders on the ground, who quickly took over the country. By the time the plane touched down in the southern city of Karachi, Musharraf was Pakistan’s new leader and Sharif was under arrest.

In September Sharif boarded a flight from London to Islamabad, but police in the Pakistani capital swiftly sent him back to Saudi Arabia.

This time, the Saudi leadership reportedly pressured Pakistan to accept him. Saudi King Abdullah provided the plane that carried Sharif home.

Ahsan Iqbal, a spokesman for Sharif’s party, said some 1,800 activists were detained in a crackdown ahead of the former premier’s return.

However, federal Information Minister Nisar Memon said he was exaggerating.

“There are no arrests as such,” Memon said. “About 100 people have been confined so that they do not create any issues. We don’t want the same mess as there was in Karachi.”

Authorities issued no warnings that Islamic militants bitterly opposed to Musharraf and Bhutto for their pro-U.S. police might target the religiously conservative Sharif.

However, his arrival came one day after suicide bombers killed up to 35 people in nearly simultaneous blasts at the heart of Pakistan’s security establishment in Rawalpindi, a garrison city adjacent to the capital, Islamabad.

It was not clear who was behind the explosions – which targeted a bus carrying intelligence agency workers and a checkpoint near army headquarters – but authorities said suspicion rested on Islamist militants who are fighting an increasingly bloody insurgency against government troops in the northwest of the country.

The army said Sunday that 30 pro-Taliban fighters and one Pakistani soldier died in an operation to capture militant positions in the Swat valley, a former tourist destination just 100 miles from Islamabad.

Musharraf cited rising religious extremism as a reason for declaration a state of emergency. However, many of those targeted under the crackdown have been political opponents, lawyers and members of the media.

More than 5,500 people have been detained since the crackdown began, but authorities insist virtually all have been freed since last weekend, when visiting U.S. Deputy Secretary of State John Negroponte urged Musharraf to restore the constitution.