Clashes have erupted in the capital Beirut and residents blocked roads in the northern Lebanese region of Akkar near Tripoli after soldiers shot dead two members of an anti-Syria opposition alliance.

Gunmen fired rocket-propelled grenades and machine guns early on Monday in intense street battles in Beirut, wounding at least six people.

The fighting appeared to be among the worst clashes in Beirut since 2008 as fears mounted that the conflict in neighboring Syria was spilling across the border.

The clashes erupted hours after Sheikh Ahmed Abdul Wahid, a Sunni Muslim cleric, and Muhammed Hussein Miraib, both members of the March 14 alliance, were shot in their car near Tripoli on Sunday as they "sped through a Lebanese army checkpoint without stopping".

Al Jazeera's Zeina Khodr, reporting from Tripoli, said that people in the area had already made their verdict and they said the army officer who carried out the shooting was allied with the Syrian government of President Bashar al-Assad.

"The very fact the anger is being directed against the Lebanese army is dangerous because it has been the only institution keeping this politically unstable country together," our correspondent said.

Over the past week Alawites, the sect to which Assad belongs, and Sunnis have been fighting each other in Tripoli, she said.

"What has become clear here is that Lebanon can no longer continue with its policy of disassociating itself with the turmoil just across the border."

Prime Minister Najib Mikati tried to quell growing tensions. "The government is determined to continue to shoulder its national responsibilities amid this critical period in Lebanon and the region, and it will take all measures necessary to preserve civil peace," he said in a statement.

The clashes in Beirut occurred in the neighborhood of Tarek Jadidah. Sources said they pitted two Sunni factions against each other - one that opposes Assad against another that is loyal to a Sunni political figure, Shaker Berjawi, who supports the Syrian president.

'Direct targeting'

Lebanon's army released a statement confirming the deaths at the checkpoint but did not give any information on who was responsible or what led to the shooting.

"The leadership of the army expresses deep regret for the death of the two victims ... It will immediately form an investigative committee comprised of senior officers and military police under the relevant court," the statement said.

Some troops had recently pulled out of Akkar to prevent tensions from escalating after sporadic fighting over the past week prompted by sectarian tensions in neighboring Syria, a security source said.
Khaled Daher, a member of parliament from the Future Movement party, which is part of the March 14 alliance, said the two men were targeted.

"If shots were fired at the tires, we would say there was a mistake. But we consider this a direct targeting from the army," he told Reuters news agency.

"Frankly, we do not want to see the army here because it works at the service of the Syrian regime," he said.

Many Sunni Muslims in Lebanon's north sympathise with Syria's uprising against Assad and say that the Lebanese army is taking orders from Damascus.

Syrian government troops were garrisoned in Lebanon until 2005.

Beirut-based political commentator Rami Khouri said the recent violence in Tripoli that killed at least eight people and wounded dozens had been linked to events in Syria.

"You have tensions in the area going back years but this has been exacerbated by the situation in Syria ... Syria is not the primary factor, but it is related," he said.

PHOTO CAPTION

Lebanese security forces stand guard near the damaged car of Sunni cleric Ahmad Abdel Wahed, killed by army troops.

Al-Jazeera