Ali Hayek clutched the photograph of his teenage son, Mahmoud, and heaved a deep sigh. "One minute he was with me and his mother was preparing his supper. Five minutes later he was shot dead in the street."
The computer student was one of seven people killed Jan. 27 when Lebanese troops fired on a crowd of Shiite antigovernment demonstrators protesting power cuts and rising bread prices.
The events of that day, now called "Black Sunday," have spurred intense accusations and recriminations from rival political factions, further souring already strained sectarian tensions in Beirut and stoking worries of more violence to come.
It has also placed the Lebanese Army on the defensive as it struggles to maintain its neutrality, even as its soldiers in recent days have come under rifle fire and grenade attack, apparent reprisals for last month's deaths.
The Army is the one state institution to have remained neutral in Lebanon's worsening political crisis. Many Lebanese believe that the military alone is preventing the country from sliding into chaos, and worry about the consequences of the Army disintegrating along political lines.
"Political quarreling is something, but attacking and disfiguring the Army is something else," says Walid Jumblatt, leader of Lebanon's Druze community and outspoken critic of the Shiite Hezbollah, which spearheads the opposition to the Western-backed government in Beirut.
Under pressure from angry Shiite leaders, the military is investigating the circumstances behind the shooting, and so far has arrested more than 20 soldiers and civilians. What remains unclear is who opened fire first – the Army, Shiite protesters, unknown agent provocateurs, or Christian gunmen from the Lebanese Forces Party.
Gen. Michel Suleiman, the commander of the Lebanese Army, has been touted as a compromise candidate for the presidency, which has remained vacant since November. However, some analysts say that the pro-Syrian opposition no longer supports General Suleiman's candidacy and are behind the drive to discredit him and the Army.
"It was a trap laid for the Army. It's an attempt to kill Suleiman's chances of being president and to sap the morale of the Army," says Oussama Safa, general director of the Lebanese Center for Policy Studies.
Other analysts suggest that the deadly outcome of the demonstration lay only in the volatile mix of angry protesters in a highly charged environment.
"It wasn't political interests that dictated the event. It happened because of street dynamics and now it's being used by political parties for their own interests," says Timur Goksel, a university lecturer in Beirut and Middle East security analyst.
Either way, the military investigation has yet to draw its conclusions, but in deeply polarized Lebanon, truth often carries less weight than perception. That much is evident from conversations with residents in the Shiite neighborhoods of Haret Hreik and Shiyyah and the Christian district of Ain Rummaneh.
"For more than 15 years, the Army has been helping the resistance, but some soldiers are allied to political parties that hate our people," says Hamad Mokdad, a Shiite Hezbollah supporter. The "resistance" is a term often used to describe Hezbollah.
Mr. Mokdad was wounded by gunfire, apparently from the Army, during the demonstration. He is being treated in a Hezbollah-funded hospital in Haret Hreik, a neighborhood of staunch support for the militants.
As news of the shootings spread through the neighborhood, residents say dozens of men carrying rifles and rocket-propelled grenades headed toward the scene, before being persuaded to turn back by Hezbollah commanders.
However, some angry Shiite demonstrators charged into the adjacent Christian neighborhood of Ain Rummaneh, damaging cars and breaking windows before troops could disperse them.
In Ain Rummaneh, a few minutes' walk from the clamor, clogged traffic, and Shiite imagery of Haret Hreik, views of "Black Sunday" are starkly different.
"I don't believe the Army did the shooting; I think it was the Shiites shooting at the soldiers that started it, because they want to provoke a war," says Lebanese Forces supporter Elie Zarour, who has a small gray mark of the cross on his forehead to commemorate Ash Wednesday.
Tensions between Ain Rummaneh and the adjacent Shiite neighborhood, Shiyyah, have existed since the 1975-90 civil war. The former Green Line dividing east and west Beirut during the war runs down the street separating the two quarters, and some buildings still bear the scars of that earlier conflict. Although the main sectarian fault-line in today's political crisis is between Shiites and Sunnis, tensions have been building once more between Shiyyah and Ain Rummaneh, residents say.
"We feel that we are heading toward a new civil war," says Hanna Nassif, a former militiaman with the Lebanese Forces. "But Ain Rummaneh is a castle of steadfastness and we will protect the Christians like we did before."