BEIRUT - Lebanon's year-old unity government collapsed Wednesday after Hezbollah ministers and their allies resigned over tensions stemming from a U.N.-backed tribunal investigating the 2005 assassination of former Prime Minister Rafik Hariri.
The walkout ushers in the country's worst political crisis since 2008 in one of the most volatile corners of the Middle East.
Prime Minister Saad Hariri, the son of the slain leader, cut short a visit to Washington after meeting with President Barack Obama. He was heading to Paris where he will meet French President Nicolas Sarkozy on Thursday, his office in Beirut said.
Hariri planned to hold consultations on his government's collapse while in France, then would return to Beirut, according to an official in Hariri's delegation who spoke on condition of anonymity to discuss sensitive diplomatic moves.
U.S. Secretary of State Hillary Rodham Clinton said the Obama administration was "consulting closely with concerned parties and nations as to the best way forward to preserve the sovereignty, stability and independence of Lebanon and the needs of the Lebanese people."
"We view what happened today as a transparent effort ... to subvert justice and to undermine Lebanon's' sovereignty and independence," she told reporters in Doha, Qatar.
The state-run National News Agency announced that 11 ministers were stepping down from the 30-member Cabinet. Hezbollah needed the backing of more than a third of the ministers to bring down the government.
The ministers had demanded the prime minister convene an urgent Cabinet meeting over the tribunal crisis, Health Minister Mohammed Jawad Khalifeh said earlier on Hezbollah's Al-Manar TV.
The tribunal is widely expected to name members of Hezbollah in upcoming indictments, which many fear could re-ignite sectarian tensions that have plagued the tiny country for decades.
"This cabinet has become a burden on the Lebanese, unable to do its work," Energy Minister Jibran Bassil said at a news conference announcing the resignations, flanked by the other ministers who are stepping down. "We are giving a chance for another government to take over."
Hezbollah, which is backed by Iran and Syria, has denounced the tribunal as an "Israeli project" and urged the Western-backed prime minister to reject any findings by the court even before it announced any indictments.
But the prime minister has refused to break cooperation with the tribunal.
Hariri's office had no immediate comment on the walkout that brought down his government while he was in Washington.
Obama and Hariri reaffirmed their commitment to strengthening Lebanon's sovereignty and independence during their Oval Office Wednesday meeting. A White House statement said Obama had commended Hariri for his "steadfast leadership and efforts to reach peace, stability and consensus in Lebanon under difficult circumstances."
"The efforts by the Hezbollah-led coalition to collapse the Lebanese government only demonstrate their own fear and determination to block the government's ability to conduct its business and advance the aspirations of all of the Lebanese people," the statement said.
The Lebanese official said Hariri was pleased with Obama's expressions of support for Lebanon.
Labor Minister Butros Harb, who is with the anti-Hezbollah bloc, told reporters after a meeting of Hariri's supporters that they are open to dialogue but "there will be no compromise over justice and the tribunal."
During Obama's meeting with Hariri, the White House said, the president also stressed the importance of the tribunal's work as a "means to help end the era of political assassinations with impunity in Lebanon." He and Hariri discussed efforts international partners to maintain calm and ensure that the tribunal's work continues without third-party interference.
The walkout followed the failure of a diplomatic push by Syria and Saudi Arabia to ease political tensions in Lebanon. There had been few details about the direction of the Syrian-Saudi initiative, but the talks were lauded as a potential Arab breakthrough, rather than a solution offered by Western powers.
Bassil said the ministers decided to resign after Hariri "succumbed to foreign and American pressures" and turned his back on the Syrian-Saudi efforts.
Calls to the tribunal seeking comment Wednesday were not immediately returned.
Hariri formed the current national unity government in November 2009, but it has struggled to function amid deep divisions. The crisis over the tribunal has paralyzed the government in recent months.
Violence has been a major concern as tensions rise in Lebanon, where Shiites, Sunnis and Christians each make up about a third of the country's 4 million people. In 2008, sectarian clashes killed 81 people and nearly plunged Lebanon into another civil war.
Rafik Hariri's assassination in a suicide bombing that killed 22 other people both stunned and polarized Lebanese. He was a Sunni who was a hero to his own community and backed by many Christians who sympathized with his efforts in the last few months of his life to reduce Syrian influence in the country. A string of assassinations of anti-Syrian politicians and public figures followed, which U.N. investigators have said may have been connected to the Hariri killing.
The Netherlands-based tribunal has not said who it will indict, but Hezbollah leader Sheik Hassan Nasrallah has said he has information that members of his group will be named.
Minutes after the Beirut Stock Exchange opened, the shares of the giant development company Solidere - the largest company listed on the stock exchange - dropped about 7 percent.