The sound of ambulance sirens rang out across Beirut as the Red Cross reported 80 wounded had been taken to hospital and 140 more were treated on site.
Riot police fired tear gas and water cannon, chasing protesters armed with tree branches and sign posts in a commercial district near Lebanon’s parliament.
Smoke billowed out of tear gas canisters encircling protesters as ambulances sped through the streets of the capital. Witnesses said security forces also fired rubber bullets.
The Internal Security Forces (ISF) said they were being “violently and directly” confronted on Saturday night. “Those who are rioting will be pursued, arrested and referred to the judiciary,” it said on Twitter.
For his part, the President Michel Aoun ordered the army and security commanders to restore calm.
While, Saad al-Hariri, who resigned as premier in October, said the violence threatened civil peace. “It is an insane, suspicious and rejected scene,” he tweeted.
After the unrest pushed Hariri to quit, feuding politicians have failed to agree on a new cabinet or rescue plan. The Lebanese pound has lost nearly half its value, dollar shortages have driven up prices and confidence in the banks has collapsed after preventing people from accessing their savings, which increased anger in the population.
Hundreds of people also had marched and chanted against the political class in other parts of the capital in the afternoon. A large banner at one of the rallies read: “If the people go hungry, they will eat their rulers.”
Crowds spilled on to the streets this week after a lull in largely peaceful protests which broke out in October. They are furious with the government that has steered the country towards its worst economic crisis in decades.
Police beatings and arrests in recent days also have alarmed human rights groups and sparked fears among activists of a move to crush the dissent.
Lebanon has witnessed three months of protests against the political elite who have ruled the country since the end of the 1975-90 civil war. The protesters blame politicians for widespread corruption and mismanagement in a country that has accumulated one of the largest debt ratios in the world.