LAHORE, Pakistan, (AP) – Opposition leader Benazir Bhutto on Tuesday urged President Gen. Pervez Musharraf to resign and ruled out serving under him in a future government after she was placed under house arrest for the second time in five days.

Bhutto also said it was now likely her Pakistan People’s Party would boycott January parliamentary elections and indicated that she wanted to build an alliance with other opposition leaders, including former Prime Minister Nawaz Sharif, to restore democracy.

“It seems unlikely that the People’s Party will participate in the upcoming elections,” Bhutto said by telephone to a group of reporters from the house in Lahore where she was being held to prevent her from leading a protest procession.

Earlier, she told private Geo TV network that Musharraf, whom she described as a hurdle to democracy, must resign both as president and army chief. She said Musharraf’s surprise declaration of an emergency and crackdown on the opposition and the judiciary meant she could no longer trust him.

“I could not serve as prime minister with Gen. Musharraf as president,” she said. “I will not be able to work with Gen. Musharraf because I simply won’t be able to believe anything he says to me.”

Her comments appeared to bury hopes of the political rivals forming a pro-U.S. alliance against rising Islamic extremism. They had held months of talks that paved the way for Bhutto’s return from exile last month to contest January parliamentary elections.

Bhutto accused Musharraf of imposing effective martial law when he declared emergency rule on Nov. 3 — suspending citizens’ rights and rounding up thousands of his opponents.

She said once she was freed from detention, she would work to forge a broad alliance, including with Sharif — a longtime rival but one who shares her wish to end military rule. Sharif was ousted by Musharraf in the 1999 coup that brought the general to power. He attempted to return to Pakistan in September but was immediately deported.

“Once I’m out, I intend to build a broad-based alliance with a one-point agenda to restore democracy,” Bhutto told reporters. “I will work with all political leaders … I will work with Nawaz Sharif.

“We may work side-by-side. The important thing is that we both believe democracy must be restored,” she said.

Authorities mounted a massive security operation to prevent her from leading a procession to the capital, Islamabad to press for an end to the emergency that Musharraf says is needed to fight rising Islamic militancy.

Thousands of riot police blocked all roads leading to the upscale neighborhood where Bhutto was staying and police said more than 100 of her supporters had been arrested in the area Tuesday.

Eight trucks and tractors loaded with sand were parked across one street. Police stood behind the vehicles and a row of metal barricades topped with barbed wire. Reporters could not see the house of a lawmaker where Bhutto was staying because they were prevented from crossing the cordon.

Bhutto’s spokeswoman, Sherry Rehman, said the former prime minister was stuck in the house with a handful of top aides. She said Punjab’s provincial government had attached the seven-day detention order as well as several padlocks to the front gate.

Aftab Cheema, chief of operations of Lahore city police, said Bhutto would not be allowed to leave the house, which was declared a “sub-jail.”

Officers detained scores of Bhutto supporters, including two lawmakers, who approached the barricades shouting slogans including “Go Musharraf go!” and “Prime Minister Benazir!”

Other Bhutto supporters apparently went ahead with the procession without her.

Shah Mahmood Qureshi, president of Bhutto’s party for Punjab, said he was leading a column of 200 vehicles from Lahore.

Police tried to stop them at several points and had waylaid some of the cars and arrested several leaders, but the convoy was continuing southward, Qureshi said by phone.

The protest caravan is expected to take about three days, and Bhutto’s party forecast that thousands of supporters would join en route.

Police initially said they ramped up security around Bhutto due to intelligence that a suicide bomber was planning to attack her in Lahore.

Bhutto was targeted by an Oct. 18 suicide attack on a homecoming procession in the southern city of Karachi as she returned from years in exile. She was unscathed, but the blast killed 145 others.

She was put under house arrest in Islamabad Friday to prevent her from addressing a rally in the nearby city of Rawalpindi, where authorities issued similar warnings.

With Musharraf losing popularity due to growing disaffection with military rule, U.S. officials encouraged him to reconcile with Bhutto in hope of keeping a U.S.-friendly administration in control of the nuclear-armed nation where militants are orchestrating attacks inside the country and across the border in Afghanistan.

Extinguishing that prospect puts further strain on Musharraf’s relations with Washington, which is pressing him loudly to lift the emergency to ensure that elections are fair. It also wants him to quit his army post.

Musharraf, who took power in a 1999 coup and became a key U.S. ally in fighting al-Qaeda and Taliban, has set no time limit for the emergency which has also resulted in a ban on rallies and the blacking out of independent TV networks.

He signaled Sunday that he wanted to hold the elections with the restrictions in place, raising major doubts over whether the vote could be credible.

The emergency came shortly before the Supreme Court was due to rule on the legality of Musharraf’s recent re-election for a new presidential term, and critics say it was a tactic to oust independent-minded judges and prolong his eight-year rule.