BEIRUT - Lebanon on Friday hosts a rare summit of regional leaders aimed at defusing tensions over reports of an impending indictment against Hezbollah members for the murder of ex-premier Rafiq Hariri.

The meeting between Lebanese President Michel Sleiman, Saudi King Abdullah and Syrian President Bashar al-Assad was hastily organised amid fears of Sunni-Shiite violence erupting in Lebanon should the UN court probing Hariri`s 2005 murder implicate the powerful Hezbollah.

Abdullah and Assad are to arrive together from Damascus and meet Sleiman before attending a luncheon to which members of Lebanon`s unity government -- which includes two Hezbollah ministers -- have been invited.

Saudi and Syrian flags were on display throughout the capital along with huge portraits of the king and a welcome message.

Security was also tight ahead of the visit, with additional army and police deployed and some streets cordoned off.

"The whole visit is about containing the situation for the immediate future," said Sahar Atrache, a Beirut-based analyst with the International Crisis Group think-tank.

"They are here to exert influence on their internal allies... to prevent a real escalation."

Assad will be visiting Lebanon for the first time since Hariri -- father of current Prime Minister Saad Hariri -- was assassinated in 2005, leading to a sharp downturn in relations between Damascus and Beirut.

Syria, as the main power broker in Lebanon at the time, was widely blamed for the murder of the Sunni former premier, but it has consistently denied any involvement.

Relations have been on the mend since 2008, when diplomatic ties were established for the first time between Beirut and Damascus. Saad Hariri has made four trips to Syria in the past eight months.

Saudi Arabia, a staunch supporter of the slain Hariri and his son, has played a key role in the rapprochement between the two countries.

The Saudi monarch is expected to press Assad to use his influence over Hezbollah, which is backed by Syria and Iran, to avoid a political stalemate or a sectarian conflict similar to the one that brought Lebanon close to civil war in 2008.

Fears of renewed conflict rose last week after Hezbollah leader Hassan Nasrallah said he knew that the UN tribunal probing Hariri`s murder was set to indict members of his Shiite party.

He made it clear that he would not accept such a scenario, accusing the tribunal of being politicised and part of an Israeli plot.

"The Arab leaders` visit to Lebanon is an opportunity to show Arab unity in the face of this plot which aims to destabilise Lebanon and sow sedition," Hezbollah deputy Hassan Fadlallah told AFP.

"This would not be in the interest of the Lebanese or their Arab brothers."

Analysts say that in addition to threatening civil peace, an indictment of Hezbollah members would deal a blow to the party`s reputation and destabilise Hariri`s unity government.

"This joint visit is historic and decisive because of its timing and the consequences it can have on a mounting crisis in Lebanon related to the tribunal," said Friday`s Arabic-language daily An-Nahar newspaper, which is close to Hariri`s coalition.

The summit will be Assad`s first visit to Lebanon since 2002 when he travelled to Beirut for an Arab summit.

King Abdullah will be the first Saudi monarch to visit the country since 1957. He also attended the 2002 summit, but was crown prince at the time.

BDST: 12:08 HRS, July 30, 2010