BEIRUT, (Reuters) – Tens of thousands of Lebanese bid farewell on Wednesday to anti-Syrian publisher and lawmaker Gebran Tueni, turning his funeral into an outpouring of anger against Damascus, which they blame for his murder.

Tueni””s assassination on Monday — the third political murder since former Prime Minister Rafik al-Hariri was killed in February — has caused serious political rifts in Lebanon, bringing the government to the verge of collapse.

In scenes reminiscent of the mass protests that swept Beirut after Hariri””s murder and forced Damascus to end a 29-year military presence in Lebanon, the crowds denounced Syria and demanded its ally, President Emile Lahoud, step down.

&#34We want your head, Bashar,&#34 the crowds chanted in reference to Syrian President Bashar al-Assad.

&#34We are here to revolt against the oppression and barbarity that is taking away our best men,&#34 mourner Nabhan Abu Samra said.

Many thousands, most of them waving Lebanese flags, answered a call by anti-Syrian politicians for a large turnout at Tueni””s funeral, carrying his flag-draped coffin on their shoulders through the streets of central Beirut to the Greek Orthodox church where a service will be held.

&#34All of Lebanon bids goodbye today to the martyr of free speech Gebran Tueni,&#34 said the frontpage headline of al-Mustaqbal newspaper, owned by the late Hariri.

The 48-year-old Tueni was among the most fiery critics of Damascus, publishing his biting editorials on the front-page of his an-Nahar newspaper, Lebanon””s leading daily.

Many Lebanese politicians have blamed Syria for Tueni””s murder, though Damascus has been quick to deny any involvement.

&#34Can no one say ””no”” in this country without being killed?&#34 asked Druze leader Walid Jumblatt, who campaigned for Syria””s withdrawal, in a call to LBC television on Tuesday night.

&#34I am threatened now … If what they want is to silence every opposition voice, then until when?&#34

A Lebanese flag was draped over Tueni””s seat in parliament, which held a special session in his honour on Wednesday. A large banner bearing Tueni””s picture was draped over the headquarters of an-Nahar in downtown Beirut.

RIFTS IN LEBANON

In Martry””s Square, the crowds also repeated the vow Tueni led them in making on the same spot at a symbolic March 14 rally: &#34We swear by God Almighty, Muslims and Christians, to remain united and defend great Lebanon forever and ever.&#34

Sanaa Mansour, dressed from head to toe in a black Islamic cloak, said: &#34We are here to show solidarity with all Lebanese, Muslims and Christians, and to call for an end to this series of deaths and for the complete liberation of our country.&#34

Five Shi””ite Muslim ministers loyal to Hizbollah and its Amal ally suspended participation in the government after it voted on Monday night to seek a U.N. inquiry into all the attacks that have rocked Lebanon over the past 14 months.

It also called for a tribunal with an &#34international character&#34 to try suspects in the murder of Hariri.

The head of a U.N. inquiry into Hariri””s assassination told the Security Council on Tuesday that the investigation could take years unless Syria speeds up its cooperation.

Detlev Mehlis has implicated Syrian and Lebanese security officials in the murder and identified six Syrians as suspects.

The Security Council also considered a resolution that France, the United States and Britain are proposing to extend the Hariri probe, which ends on Thursday, for six months.

The draft would expand the commission””s mandate &#34to include investigations on the terrorist attacks perpetrated in Lebanon since Oct 1, 2004 at the discretion of the commission.&#34