The protest movement forced the resignation of prime minister Saad Hariri on October 29 and official talks to name his replacement are to start on Monday.
Security forces on Saturday fired tear gas and rubber bullets at protesters in Beirut, some of whom tried to break into a barricaded central district of Lebanon's capital.
Hundreds of people were gathered as part of a wave of protests that have swept Lebanon since October 17, furious at a ruling elite that steered the country towards its worst economic crisis in decades.
Since the protests pushed Saad Hariri to resign as prime minister in late October, talks between the main parties have been deadlocked over forming a new cabinet.
Lebanon urgently needs a new government to pull it out of the crisis which has also shaken confidence in its banking system. Foreign donors say they will only help after the country gets a cabinet that can enact reforms.
Riot police and security forces deployed en masse in Beirut on Saturday night, chasing demonstrators in the street, beating and detaining some of them, a Reuters witness and a protester said.
The forces fired tear gas canisters and rubber bullets as some protesters tried to push through steel barriers blocking paths to the parliament and government headquarters.
State news agency NNA said the tear gas had made several people faint, while the Lebanese Red Cross said 14 people were injured, six of them badly enough to need taking to hospital.
The unrest erupted from a build-up of anger at the rising cost of living, new tax plans and the record of leaders dominating the country since the 1975-90 civil war. Protesters accuse the political class of milking the state for their own benefit through networks of patronage.