Lebanon's president asked Saad Al-Hariri to stay on as caretaker prime minister on Thursday after Hezbollah ministers and their allies resigned in a dispute over an investigation into the killing of Hariri's father.

A statement issued by President Michel Suleiman called on the government to "continue in a caretaker capacity until a new government is formed".

Hariri, who was meeting US President Barack Obama in Washington when his fragile, 14-month-old "unity" government collapsed on Wednesday, was due to hold talks in Paris later on Thursday with French President Nicolas Sarkozy.   

The resignations of the 11 ministers followed the failure of regional powers Saudi Arabia and Syria to forge a deal to reduce tension over the UN-backed investigation into Rafik Al-Hariri's 2005 assassination.   

The tribunal prosecutor is expected to send draft indictments to a pre-trial judge this month, and Hezbollah leader Sayyed Nasrallah has said he expects members of his Shi'ite movement to be accused of involvement.   

Hezbollah denies any role in the killing and had called on Hariri to withdraw Lebanon's funding for and cooperation with the tribunal -- a demand which he rejected.   

Analysts played down the prospect of open armed conflict between Hezbollah, which is backed by Syria and Iran, and Hariri, who is supported by Saudi Arabia and the United States.   

Arab League Secretary-General Amr Moussa said that while Hariri's killers should be punished, any immediate move to hand down indictments naming Hezbollah could inflame matters further.

"The tribunal should be above politics and justice should have its say and Lebanon must have a government," Moussa said in the Qatari capital of Doha on Thursday.

"But since we were waiting for several years, why not six more months of time in order to defuse the situation? ... It is very threatening," he said. - Reuters