Beirut, Jan 12 (Agencies): Lebanon's unity government collapsed on Wednesday after the powerful Hezbollah and its allies resigned from the cabinet over a UN probe into the assassination of former premier Rafiq Hariri.

Energy Minister Gebran Bassil told a press conference that 10 ministers from the 30-member cabinet had tendered their resignations because of a long-running dispute with Prime Minister Saad Hariri -- son of the slain leader – over the Special Tribunal for Lebanon.

The announcement by Bassil, a member of the Christian Free Patriotic Movement close to Hezbollah, came just as Hariri was meeting in Washington with US President Barack Obama on the crisis.

An 11th minister close to President Michel Sleiman also quit on Wednesday, thus providing the number of resignations needed to topple the government.

The Shiite militant group Hezbollah and its allies have for months been pressing Hariri to disavow the STL on the grounds that it is part of a US-Israeli plot.

Hezbollah's camp, which is backed by Iran and Syria, on Tuesday gave the Western-backed Hariri until Wednesday to convene a cabinet meeting on the tribunal.

Environment Minister Mohammad Rahhal, who is close to Hariri, said Hezbollah's decision to quit the government was aimed at paralysing the state and forcing the premier to reject the tribunal.

"They think that by piling the pressure on him, Hariri will bend but they are mistaken," Rahhal said.

The Sunni premier has held talks in recent days in New York with Saudi King Abdullah, US Secretary of State Hillary Clinton, French President Nicolas Sarkozy and UN Secretary General Ban Ki-moon over the crisis.

"They want Hariri to enter the meeting with the US president as an ex-premier or as head of a caretaker government," Alloush said. "But the real goal is to deal a moral blow to the United States."

Syria and Saudi Arabia have for months been attempting to mediate the crisis but their efforts have failed, with rival Lebanese camps accusing each other of blocking attempts at a compromise.