I saw a Lebanese fighter hoist the Syria opposition flag on a sandbag barrier on the frontline between two Lebanese communities who shot at each other for days last week.

It wasn't the first time Sunnis of Bab el-Tebbaneh and the Alawites (the sect of Syrian president Bashar Assad) used weapons against each other. This flashpoint neighborhood in the northern city of Tripoli has long been a battleground.

"Every time there is a flare up of violence... It is because of the political situation. This time they believe our area belongs to the Free Syrian Army and Jabal Mohsen neighborhood is a base for the Syrian regime," Sheikh Walid Tabbouleh, an Imam of a mosque in Bab el-Tebbaneh said.

That is not far from the dangerous reality on the ground, where there is no shortage of weapons.

Many Sunnis in Bab el-Tebbaneh are supporting the uprising across the border and they don't hide this.

Just walk through the narrow alleyways of Bab el-Tebbaneh - Syrian opposition flags are everywhere. People tell you they are ready to sell everything they have to buy weapons for the Free Syrian Army. 

The Alawites are standing behind the Syrian government. In their neighborhood, it is posters of Bashar al-Assad that dot the walls.

Yet again the Lebanese army was deployed along a street that separates the two sides. A street which name is the subject that divides them: Syria.

Many Sunnis claimed the division of the army that was sent to contain the tensions was close to the Syrian government. 

Army in the middle

The army, seen as the only force holding this politically unstable country together, was in danger of getting sucked into the divisions. 

The danger is still there. The army is now at the center of the latest conflict. A soldier opened fire and killed a Sunni cleric and his bodyguard near a checkpoint in the northern region of Halba.

The people of the region called it an assassination - the cleric was a member of the anti-Syria government March 14 alliance.

"He (the soldier) was a member of Lebanese groups allied to the Damascus government," protesters claimed.

The army opened an investigation but sources said "the army would never shoot anyone without a reason. A soldier was wounded and there was an exchange of fire".

Lebanon is no longer capable of maintaining its official policy of self-dissociation over the crisis across the border in Syria. This has become evident in Tripoli and surrounding regions close to the border. 

This area is friendly territory for the Syrian opposition. Some Lebanese factions here not only sympathize with their cause but have had a long history of animosity with the Damascus government. 

Allies of the Syrian government here however believe this city has become an operational base for the Syrian opposition.

Buffer zone

North Lebanon is where the Syrian government alleges its opponents are planning to create a buffer zone.

In a letter to the United Nations, Syria said Lebanon is the source of terrorism in the country.

"Some Lebanese areas next to the Syrian border are incubating terrorist elements from Al-Qaeda and the Muslim Brotherhood, who are messing with the security of Syrian citizens and working on undermining the United Nations Special Envoy's [Kofi Annan] plan," the letter said.

"It is irrelevant whether the Syrian opposition plans to do that, we (Lebanon government) will not allow anyone to use the north or any other area of the country to form an isolated area where the opposition can have freedom of movement and training outside the eyes of the state," State Minister Marwan Khaireddine told me. 

Lebanon is yet again in crisis. Skirmishes in flash-point neighborhoods in the Lebanese capital on Sunday night, in response to the cleric's killing, were the worse since former Prime Minister Saad Hariri's government collapsed in January 2011.

It was members of his group which first took the streets before clashing with rival parties.

Foe the time being, Damascus' allies have the upper hand - the balance of power is in their favor - they control the government.

Undoubtedly Syria's conflict is affecting Lebanon. It was not unexpected. After all, it is Syria that has long divided the Lebanese.