Hezbollah and allies topple Lebanese unity government
Lebanon's national unity government has collapsed after 11 ministers from Hezbollah and its allies resigned.
Energy Minister Gibran Bassil said the decision was prompted by a dispute over the UN tribunal investigating former Prime Minister Rafik Hariri's murder.
The announcement came as Prime Minister Saad Hariri, his son, was meeting US President Barack Obama in Washington.
Tension has been high in Lebanon, amid indications that Hezbollah members could be indicted by the UN tribunal.
On Tuesday, officials said efforts by the Syrian and Saudi Arabian governments to reach a political compromise had failed. The opposition has claimed that a potential deal was blocked by the US.
After meeting Mr Hariri, Mr Obama said the latest moves demonstrated Hezbollah's determination to block the government's work.
There are widespread fears that a collapse of the government could spark an outbreak of sectarian violence, last seen in Beirut in 2008.
Under a power-sharing deal agreed in November 2009 to end five months of deadlock, the Shia Islamist movement Hezbollah was given two posts in the 30-member national unity government.
Its allies - the Shia Amal movement and the bloc of the Maronite Christian leader and former general Michel Aoun - got another eight.
Mr Hariri's Sunni Future movement and its Maronite Christian and Druze allies, meanwhile, had 15 ministers in the cabinet.
The five remaining ministers were named by President Michel Suleiman.
The resignations of more than a third of the ministers were required to bring down the government.
On Wednesday, the 10 ministers allied to Hezbollah were joined by one of the president's appointees, Minister of State Adnan Sayyed Hussein, in announcing that they would resign and force the government's collapse.
Mr Hariri will now head a caretaker administration while the president consults parliamentary blocs to seek agreement on an acceptable new figure.
Mr Bassil, a member of the Christian Free Patriotic Movement, said the prime minister had rejected their demands for an urgent cabinet session to discuss withdrawing all co-operation with the UN-backed Special Tribunal for Lebanon (STL) and denouncing any indictments.
"The grace period has ended, and the waiting stage that we lived through without any result has ended," he told Reuters news agency.
Environment Minister Mohammed Rahhal, a member of the Future Movement, said the resignations were aimed at paralysing the state and forcing Mr Hariri to reject the authority of the tribunal investigating his father's murder, something he could not bring himself to do.
"They think that by piling the pressure on him, that Hariri will bend, but they are mistaken," he told the AFP news agency.
Other allies of the prime minister criticised Hezbollah for making the announcement coincide with his meeting with President Obama.
Mr Hariri made no comment after the talks at the White House, but officials said he planned to fly to Paris this evening to discuss the crisis with French President Nicolas Sarkozy before returning to Beirut.
A White House statement said President Obama had commended Mr 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," it said.
BBC Beirut correspondent Jim Muir says this is believed to be the first time in Lebanon's history that a government has been brought down by ministerial resignations rather than the prime minister himself deciding to call it a day.
This is a struggle over the regional balance of power, which was heavily in Washington's favour at the time the UN tribunal was established, but has now swung back in the direction of Syria, Iran and their local allies on the Lebanese stage, our correspondent says.
But, he adds, while bringing down the government is one thing, replacing it with another is something else.
At the moment, Mr Hariri's allies insist that only he should head any new government. So getting them to agree to someone closer to Syria and the Lebanese opposition will be very hard, our correspondent says.
President Suleiman will go through the motions to find a compromise candidate, but the consultations are likely to go round in circles as long as there is no agreement, and certainly there is none in sight, he adds.
Rafik Hariri and 22 others were killed in February 2005 when a huge bomb exploded next to his motorcade in Beirut.
Syria was initially blamed for the assassination, and eventually forced in its wake to withdraw its troops from Lebanon after 29 years. In the past year, however, members of Hezbollah have emerged as prime suspects.
The Canadian broadcaster, CBC, reported in November that evidence gathered by the Lebanese police and the UN pointed "overwhelmingly to the fact that the assassins were from Hezbollah".
It published diagrams showing how investigators had traced interlinking networks of mobile phones from the vicinity of the blast that killed Rafik Hariri to Hezbollah's communications centre in south Beirut.
Hezbollah has rejected any suggestion of involvement in the assassination. Its leader, Hassan Nasrallah, has called the tribunal an "Israeli project" and warned of dire consequences if it indicts his followers.