By Tom Perry and Alaa Kanaan
BEIRUT (Reuters) - A large fire erupted at Beirut port on Thursday, engulfing parts of the Lebanese capital in a pall of smoke weeks after a massive blast devastated the port and ruined a swathe of the city.
The blaze began in the shattered duty free zone of the port, prompting some residents to flee the city still traumatised by last month's explosion that had followed a port fire.
Army helicopters dropped water as firefighters battled on the ground to bring the blaze under control. By nightfall, officials said most flames had been extinguished. Smoke still rose from smouldering wreckage but it was far less dense.
The blaze strained nerves already on edge. The city is reeling from the Aug. 4 port blast and the nation is grappling with a deep economic crisis that has posed the biggest threat to Lebanon's stability since its 1975-1990 civil war.
"For sure we were scared, it's only been a month since the explosion that destroyed Beirut. We saw the same thing happening again," 53-year-old Andre Muarbes said after soot and ash settled on vehicles and buildings across parts of the capital.
Lebanese President Michel Aoun told top security officials meeting about the blaze that the fire could have been the result of sabotage, technical error or negligence, and the cause had to be uncovered quickly.
Many Lebanese are frustrated that they have yet to be told about any initial findings from an investigation into last month's port explosion that killed about 190 and injured 6,000.
Officials said no one had been injured in Thursday's fire although some suffered shortness of breath.
Michel Najjar, public works minister in the outgoing government which resigned in the wake of the blast, told Lebanon's MTV initial indications suggested the blaze was sparked by welding work during repairs at the port.
A security source had also blamed welding work for the fire preceding the Aug. 4 blast.
SHOCK
The Geneva-based International Committee of the Red Cross said it had aid in a warehouse that was on fire. "Our humanitarian operation risks to be seriously disrupted," ICRC Middle East director Frabrizio Carboni wrote on Twitter.
Beirut's port is used by aid agencies to supply refugees in Lebanon and people in need in neighbouring Syria.
A military source said Thursday's blaze appeared to have started when cooking oil caught fire and spread to stores of tyres. Television footage had shown flames licking up near a pile of tyres in a warehouse ruined in last month's explosion.
Majed Hassanein, 49, was taking his wife and two children out of the capital by car during the height of the blaze. "I am forced to get them out of Beirut from the smoke and the fire that is happening at the port again," he said.
He said his son still suffered from shock from the blast that ruined a swathe of capital and left about 300,000 people without inhabitable homes and shattering windows across Beirut.
Carmen Geha, an activist and associate professor at the American University of Beirut, said the fire was further proof of mismanagement by a ruling elite, who have dragged the nation into crisis after years of corruption and poor governance.
"It's a gross crime, gross negligence and gross arrogance," she said. "You can't trust them to manage anything."
Firefighters were shown on television dousing the fire surrounded by mangled remains of warehouses destroyed in last month's explosion, which was caused by a store of ammonium nitrate kept in poor condition at the port for years.