BEIRUT (Lebanon) • From the moment Mr Saad al-Hariri's plane touched down in Saudi Arabia on Nov 3, he was in for a surprise.

There was no line-up of Saudi princes or government officials, as would typically greet a prime minister on an official visit to meet King Salman, senior sources close to Mr Hariri and top Lebanese political and security officials said. His phone was confiscated, and the next day he was forced to resign as prime minister in a statement broadcast by a Saudi-owned TV channel.

The move thrust Lebanon back to the forefront of a struggle that is reshaping the Middle East, between the conservative Sunni monarchy of Saudi Arabia and Shi'ite revolutionary Iran.

Their rivalry has fuelled conflicts in Iraq, Syria and Yemen, where they back opposing sides, and now risks destabilising Lebanon, where Riyadh has long tried to weaken the Iran-backed Hizbollah group, Lebanon's main political power and part of the ruling coalition.

Sources close to Mr Hariri said Saudi Arabia has concluded that the prime minister - a long-time Saudi ally and son of late premier Rafik al-Hariri, who was assassinated in 2005 - had to go because he was unwilling to confront Hizbollah.

Multiple Lebanese sources said Riyadh hopes to replace Mr Saad al-Hariri with his older brother Bahaa as Lebanon's top Sunni politician.

The elder brother is believed to be in Saudi Arabia and members of the Hariri family have been asked to travel there to pledge allegiance to him, but have refused, the sources said.

Mr Hariri was summoned to meet King Salman in a phone call on Nov 2. The sources said Mr Hariri believed he had convinced Saudi officials of the need to maintain an entente with Hizbollah for the sake of Lebanon's stability.

"What happened in those meetings, I believe, is that (Mr Hariri) revealed his position on how to deal with Hizbollah in Lebanon: that confrontation would destabilise the country. I think they didn't like what they heard," said one of the sources who was briefed on the meetings.

Mr Hariri's resignation speech shocked his team. Lebanese President Michel Aoun, a Hizbollah ally, told ambassadors to Lebanon that Saudi Arabia had kidnapped Mr Hariri, a senior Lebanese official said.

Initially there was speculation that Mr Hariri was a target of an anti-corruption purge in Saudi Arabia because of his family's business interests. But sources close to the Lebanese leader said his forced resignation was motivated by Saudi efforts to counter Iran.

Family members, aides and politicians who have contacted Mr Hariri in Riyadh say he is apprehensive and reluctant to say anything beyond "I am fine".

Asked if he is coming back, they say his normal answer is: "Inshallah" (God willing).

REUTERS