Hundreds of angry protesters burnt tyres and blocked roads across Lebanon Tuesday after a Hezbollah-backed politician was named prime minister, shifting the balance of power in the country towards Syria and Iran.

The nomination of Najib Mikati is seen as a victory for Hezbollah, which is trying to fend off a U.N.-backed tribunal set up in 2005 to try the killers of statesman Rafik al-Hariri and which is expected to accuse members of the Shi'ite group.

Sunni Muslims loyal to outgoing premier Saad al-Hariri, Rafik's son who has Western and Saudi backing, staged a day of rage to protest the appointment of Sunni billionaire Mikati, a centrist lawmaker with ties to both Saudi Arabia and Syria.

Hezbollah's enhanced political strength will set off alarm bells in Washington and across the region, especially in Israel which in 2006 fought a five-week war in a failed attempt to destroy the Iran-backed movement's formidable military capacity.

Israeli officials have since threatened regularly to respond to Hezbollah's arsenal of rockets in Lebanon, upgraded with help from Syria and Iran.

Mikati, a telecoms tycoon who has portrayed himself as a consensus candidate, said he would start talks to form a government Thursday and appealed to all Lebanese factions to overcome their differences.

All Lebanese leaders should cooperate together to face the current challenges, he said from the presidential palace after he accepted his nomination by President Michel Suleiman.

I reiterate my position ... that my hand is extended to all factions to take part and end division...through dialogue.

Hezbollah and its allies quit Hariri's unity government earlier this month, bringing it down after the failure of a Syrian-Saudi effort to bridge a rift over the tribunal.

Hezbollah leader Sayyed Hassan Nasrallah urged Mikati to form a national partnership government.

We have supported the nomination of ... Mikati and we call on him to form a national partnership government. The Lebanese have a chance to close ranks, he told thousands of supporters.


Nasrallah said Mikati was not the Shi'ite group's candidate, but it had backed him as a compromise figure.

Hezbollah and its allies did not want to break bones with the other side ... (nor) form a one-sided government, he said.

Nasrallah's priority is for Lebanon to repudiate the tribunal, which issued still-secret indictments last week that are widely expected to implicate Hezbollah members in Hariri's assassination, a charge the Shi'ite group denies.

France said it was important that the new government was formed free from interference and through dialogue.

We urge the incoming government to respect international commitments made by Lebanon, and particularly for the Special Tribunal for Lebanon, French foreign Ministry spokesman Bernard Valero said.

Hezbollah's role in bringing down Hariri's government will also raise concerns in Sunni Arab states, wary of Iran's influence in the region.

The biggest protest took place in the northern city of Tripoli where medical sources said 20 people were treated for injuries and protesters set fire to a satellite truck used by the Arab television channel Al Jazeera.

Hariri appealed for calm, saying he rejected demonstrations of violence. You are angry but you are responsible people. I understand your feelings, he told supporters in a televised speech.This anger should not lead us to what disagrees with our values ... our belief that democracy is our refuge.

Sunni blood is boiling chanted protesters in Tripoli, urging Mikati to withdraw his nomination and waving flags of Hariri's Future Movement which says it will not serve in any government dominated by the militant Shi'ite group.

Hezbollah and its allies shifted the power in Lebanon legally and constitutionally, winning support for Mikati from 68 of parliament's 128 members after Druze leader Walid Jumblatt, once a Hariri ally, switched sides.

In Beirut, protesters blocked a road with burning tyres and overturned garbage containers. A security source said shots were fired in the air and the army intervened, but no one was hurt.

Lebanon's power-sharing political system calls for the post of prime minister to be held by a Sunni, and Hariri supporters said any figure who accepted the nomination from the Shi'ite group to form a new government would be considered a traitor.

Hezbollah and its allies walked out of Hariri's unity government in dispute over still confidential indictments by a U.N.-backed tribunal. The group had asked Hariri to cut Lebanon's links with the tribunal but he rejected.

Politicians allied to Hezbollah have said the first priority of their new government would be to cut links with the tribunal, which is expected to accuse Hezbollah members of involvement in the 2005 killing. Hezbollah denies any role.

Hariri supporter Mustafa Alloush told the crowd in Tripoli Tuesday that the overthrow of the government two weeks ago was part of an Iranian takeover. It's an attempt to bring Lebanon into the Persian sphere. We will not accept that, and we will be on alert for them, he said.