READERS of Lebanon's Daily Star awoke to some cheerful news on Tuesday. "Ray of hope shines on Beirut as both sides see 'open door"' read the page one headline, referring to new hopes of reducing sectarian tensions.

Then, shortly after 9am, two bombs exploded in two minibuses travelling past the mountain home of the Gemayel clan, Lebanon's leading Christian political dynasty, killing three people and injuring 20.

A day later, as tens of thousands gathered in Beirut to mark the second anniversary of the murder of the former prime minister Rafiq Hariri, the ray of hope already looked like a flash in the pan.

No one claimed responsibility for Tuesday's bombings. However, it is seen as an attempt to disrupt efforts to ease a two-month sectarian stand-off in Beirut.

For supporters of the Prime Minister, Fouad Siniora, the timing and target of the attacks implicate Syria. Five of Syria's enemies in Lebanon, including Mr Hariri and the minister Pierre Gemayel, have been mysteriously murdered over the past two years.

They believe that Mr Hariri, the leader of Lebanon's moderate Sunni Muslims, was killed two years ago for backing a campaign to end two decades of Syrian military hegemony in Lebanon.

The backlash against the massive bomb that killed Mr Hariri and 22 others forced Damascus to withdraw its troops two months later. But the assassinations of anti-Syrian politicians and journalists have continued.

Mr Siniora's ruling coalition believes Damascus now wants to claw back some of its former influence and to stymie a United Nations investigation into the recent assassinations.

The political crisis pits anti-Syrian government supporters against an opposition bloc led by the Syrian- and Iranian-backed Shiite Muslim militant group Hezbollah, and a breakaway faction of Maronite Christians led by General Michel Aoun. Since December supporters of Hezbollah and General Aoun have been camped outside the Prime Minister's office. They accuse him of collaborating with the US and Israel and are demanding that he and his government resign.

At least nine people have died in clashes between the rival blocs, raising the spectre of a return to the civil war of the 1970s and '80s.

Mr Siniora's backers accuse Syria of using its allies to engineer a political stalemate that blocks Lebanese involvement in the Hariri murder investigation. A key Hezbollah ally, the parliamentary Speaker Nabih Berri, has refused to recall parliament to allow debate on the issue.

In recent days a "ray of hope" did begin to distantly glimmer. With the US still committed to boycotting its enemies in the Middle East, its chief Sunni Muslim ally Saudi Arabia contacted Shiite Muslim Iran and secular Syria in a an effort to reduce Sunni-Shiite violence in Iraq, Lebanon and across the region.

After contacts between Riyadh, Tehran and Beirut, Mr Berri surprised many in Lebanon by announcing he would seek to co-operate with the Hariri inquiry. Hezbollah has repeatedly said it is not against an investigation, but that it does not want it to become a political weapon against itself or its allies.

However, in Damascus the regime of President Bashar Assad, whose officials have already been implicated by the UN investigation, is reported to have reservations.

Tuesday's bombing suggests that somebody certainly does.