Lebanon’s interior minister says five people have been killed in armed clashes in Beirut that erupted Thursday during protests against the lead investigator looking into last year’s massive blast at the city’s port.

Bassam Mawlawi told reporters Thursday that five people were killed. Many of those injured were shot by snipers from buildings, he added, calling the events, "a very dangerous sign.”

The protest outside the Justice Palace was called for by the powerful Hezbollah group and its allies, who are demanding the removal of Judge Tarek Bitar. A journalist with The Associated Press (AP) saw one man open fire with a pistol during the protest. People ran for cover as shots and ambulance sirens could be heard in a live broadcast by Lebanon's Al-Jadeed TV.

The exchanges of fire involving snipers, pistols, Kalashnikovs and rocket-propelled grenades were a dangerous escalation of tensions over the domestic probe, and the worst armed clashes since 2008, when the Hezbollah briefly overran parts of Beirut. It was not immediately clear how Thursday’s clashes began, but tensions had been running high after the Hezbollah and its allies from the Amal group, the country's main Shiite parties, called for a protest near the Justice Palace, along a former civil war front line between Muslim and Christian areas.

In a statement Thursday, the two groups said their protesters came under fire from snipers deployed on rooftops in the Tayouneh area, which is located on the border between Christian and Muslim neighborhoods of Beirut and was a front line in the 1975-90 civil war. It is on the way from the predominantly southern suburbs of Beirut to the Justice Palace, where the protest was due to take place. The Iranian-backed group said that protesters were attacked by gunmen from the right-wing Lebanese Forces (LF) party.

The right-wing Christian LF mobilized supporters Wednesday evening in a predominantly-Christian area. Videos circulating on social media showed supporters of Christian LF marching in the streets, carrying large crosses.

Gunfire echoed in the capital for several hours and ambulances, sirens wailing, rushed to pick up casualties. Snipers shot from buildings. Bullets penetrated apartment windows in the area. Four projectiles fell near a private French school, Freres of Furn el Chebbak, causing panic, a security official said, speaking on condition of anonymity because he was not authorized to speak to the press.

The students huddled in the central corridors with the windows open to avoid major impact, in scenes reminiscent of the 1975-90 civil war. Smoke covered the neighborhood where intense gunfire was relentless. A car caught fire, while a blaze was reported in a lower floor where residents were stuck and called for help. The violence unfolded while U.S. Undersecretary of State for Political Affairs Victoria Nuland was in town, meeting with Lebanese officials. Her schedule was slightly thrown off by the action on the streets.

The army deployed heavily and sent patrols to the area to search for the gunmen, following the exchanges of gunfire between the Muslim and Christian sides of the capital.

One man died of a gun shot to the head and a second of a shot to the chest, said Mariam Hassan of Sahel Hospital. A 24-year-old woman was hit in the head by a stray bullet while inside her home, the doctor added. The state-run National News Agency (NNA) reported a fourth death at the Rasoul al-Azam hospital, also in the southern suburbs.

The Lebanese Red Cross said 30 people had been wounded. Lebanese television broadcast images of men carrying rifles and heavy weaponry, according to Agence France-Presse (AFP).

In a statement, Prime Minister Najib Mikati appealed for calm and urged people "not to be dragged into civil strife.”

Hundreds of tons of ammonium nitrates that had been improperly stored at a port warehouse detonated on Aug. 4, 2020, killing at least 215 people, injuring thousands and destroying parts of nearby neighborhoods. It was one of the largest non-nuclear explosions in history and has further devastated the country already roiled by political divisions and unprecedented economic and financial meltdown.

Bitar, the second judge to lead the complicated investigation, has come up against formidable opposition from Lebanon’s powerful Hezbollah group and its allies who accuse him of singling out politicians for questioning, most of them allied with Hezbollah. None of Hezbollah’s officials have so far been charged in the 14-month-old investigation.

The shooting continued even after army troops deployed to the area Thursday, with the sound of exchange of fire ringing over their heads. Residents and civilians in the area were ducking to avoid the shooting, some screaming: "Some martyrs on the ground!” People pulled one man who was apparently shot and down, away from the line of fire.

The armed clash could derail the country’s month-old government of Mikati even before it begins tackling Lebanon’s unprecedented economic crisis. A Cabinet meeting was canceled Wednesday after Hezbollah demanded urgent government action against the judge.