Syria and Saudi Arabia have stepped up efforts to ease a political crisis in Lebanon over a UN probe into the murder of ex-premier Rafiq Hariri, Information Minister Tareq Mitri said on Thursday.

"Saudi Arabia and Syria have reminded all the Lebanese political forces that they still see themselves as guarantors of stability and strongly encouraged them to put an end to their inflammatory rhetoric and to calm down," Information Minister Tareq Mitri told reporters.

The fragile government has been shaken by disputes over the UN-backed probe into the murder of Hariri's father, Rafiq Hariri, who died in a massive seaside bombing in 2005.

The mudslinging between Hariri's Western- and Saudi-backed coalition and Hezbollah includes arguments about its funding and controversy over 'false witnesses' and over a pro-Syrian general who was jailed in connection with Hariri's killing.

Syrian President Bashar al-Assad, a key supporter of Hezbollah along with Iran, contacted Prime Minister Saad Hariri on late Wednesday to discuss developments, Hariri's office said.

But the heated rhetoric is unlikely to die down in the run-up to indictments expected against members of pro-Syrian Shi'ite Hezbollah for alleged involvement in the killing, that pushed Lebanon into crisis in 2008.

Hezbollah
Hezbollah has denounced the U.N. tribunal as an Israeli project, denied involvement in the attack and blamed Israel for killing Hariri, whose son Saad now leads the unity government.

The Iranian and Syrian-backed group and its allies have also sought to head off the indictments by questioning the credibility of the investigation and accusing it of relying on false testimony and telephone records that Israeli spies could have manipulated.

Syria
Syria has repeatedly denied involvement in the assassination which provoked an international outcry against it and forced the country to end its three decade military presence in Lebanon.

Saad Hariri has since mended relations with Damascus, visiting Assad several times and emphasising Lebanon's need for strong ties with its bigger neighbour.

And in a stunning turnaround, Hariri said he was wrong to accuse Syria of killing his father and that the charges against Damascus had been politically motivated.

Tribunal
In late 2005, Lebanon asked the United Nations to establish a tribunal of international character to try those allegedly responsible for the February 14, 2005 attack that killed Hariri and the others.

Pursuant to a Security Council resolution the following year, the STL was created following negotiations between the two parties.

The tribunal, based in The Netherlands, formally began operation in 2009.

(Source: AFP, Reuters)