The explosion that tore through a southern suburb of the Lebanese capital Tuesday is prompting yet more fears that Lebanon risks being dragged into the civil war raging in neighboring Syria.
The explosion was viewed here by many analysts as apparent retaliation by Sunni militants for the Shi'ite Hezbollah movement's military support of Syrian President Bashar al-Assad. The bomb exploded at mid-morning in the densely populated southern suburb of Dahyeh, where the bombers managed to breach heavy security and maneuver the car into Hezbollah's so-called "security square" where many of the movement's leadership work and live.
For some analysts the bombing doesn't come as a surprise.
Lebanese author Michael Young warns that Syria's sectarian-based civil war and Hezbollah's role in it is worsening divisions between Lebanese Sunni Muslims and Shi'ites.
"It doesn't like to be tagged just as a sectarian Shi'ite party. But the relations between Lebanon's Shi'ites and Sunnis have been tense for several years particularly after the 2006 war. So the fact that today they are intervening on the side of the Syrian regime has really only exacerbated a problem that has been there for several years," he said.
Lebanon is deeply divided over the Syrian conflict next door. The majority of Sunnis support the opposition, while Shi'ites back President Bashar al-Assad, one of Hezbollah's regional patrons along with Iran. The violence from Syria has spilled over to Lebanon with occasional armed clashes, most recently in Sidon between Sunni militants and the Lebanese army that left 18 soldiers dead.
Tuesday's attack is not the first this year on Hezbollah's Beirut suburb. Back in May, less than 12 hours after the Hezbollah leader, Hassan Nasrallah, gave a speech acknowledging his Shia militia was intervening in Syria, rockets were launched from the foothills of the Druze mountains targeting the suburb but fell short. It wasn't clear who fired them - as it isn't clear who was responsible for Tuesday's car bombing.
The country's president, Michel Suleiman, echoed the fears of many Lebanese when he denounced Tuesday's explosion saying it was a "reminder of the black days experienced by the Lebanese in the past."
The biggest worry is that attacks like Tuesday's bombing could re-ignite Lebanon's brutal sectarian civil war of 1975-1990 that left 120,000 dead.
Retired general Hisham Jaber believes that the situation can be controlled and that neither Hezbollah nor Sunni militants want a full-scale conflict on Lebanese soil as the country is useful as a logistical base for both sides when it comes to Syria. But he warns that may not always be the case.
"But let me be frank with you. If the situation in Syria will change in a dramatic way, let's say the regime will collapse, let's say there is any dramatic change in Damascus or the assassination of the head of the regime. In this case it will move directly to Lebanon and we will lose control," he said.
How Hezbollah reacts to the car bombing in its stronghold will prove crucial.