Almost 400 people were wounded Saturday during running battles between anti-government protesters and Lebanese security forces in the capital Beirut, rescuers said.

It was the heaviest toll since the protests erupted three months ago, with the Red Cross and Civil Defence saying 377 people at least were rushed to hospital or treated at the scene.

The protest movement rocking Lebanon since Oct. 17 has revived this week, over delays in forming a new cabinet to address the country's growing economic crisis.

Reports also said fire engulfed a protest camp in the evening, burning tents and sending plumes of smoke into the air.

Protesters also threw firecrackers at police.

Security forces sprayed young men with two water cannons and lobbed tear gas over a metal fence to disperse remaining protesters on the wet tarmac.

On Saturday afternoon, demonstrators set out from various spots in Beirut in a march towards the city center under the slogan "We won't pay the price."

"A direct and violent confrontation is taking place with anti-riot police at one of the entrances to parliament," the Internal Security Forces said on Twitter.

"We ask peaceful protesters to keep away from the site of the rioting for their safety."

An AFP photographer saw young men uproot parking meters.

He also saw around 10 people faint from the tear gas.

A female protester named Maya, 23, said she was attending the protest because politicians still seemed to be ignoring demands for an overhaul of the old political class.

"I'm here because after more than 90 days in the streets, they're still squabbling over their shares in government... It's as if they didn't see our movement," she told AFP.

"Popular anger is the solution," the young protester said.

Forming a new cabinet is often convoluted in Lebanon, where a complex system seeks to maintain a balance between the country's many political parties and religious confessions.

But protesters say they want to scrap the old system, and demand only impartial technocrats staff a new government to address their growing economic woes, including a severe liquidity crisis.

The last government stepped down under pressure from the street on October 29, but has remained in a caretaker capacity until a new cabinet takes shape.

The World Bank has warned that the poverty rate in Lebanon could rise from a third to a half if the political crisis is not remedied fast.