Demonstrations were held across France late Sunday following the results of the country's snap parliamentary election.
People took to the streets in several cities to celebrate the surprise victory of the left-wing alliance according to preliminary results.
Tensions rose in Republique Square in central Paris, where police intervened against protesters, the Le Figaro daily reported.
Some groups wearing masks set fire to objects in the streets, it added.
In the northern city of Lille, police reportedly used tear gas against 500 members of an "anti-fascist" group.
Southern Marseille was also jolted by protests involving 5,000 people, police said, with the crowd chanting slogans against the far right, according to Le Figaro.
In the western city of Rennes, police arrested 25 people when tensions rose and used tear gas to disperse an unauthorized and spontaneous demonstration.
The leftist New Popular Front (NPF) alliance could win 187 to 198 seats in parliament's lower chamber, the National Assembly, according to the latest projections based on surveying company Ifop's estimates.
The centrist Together for the Republic alliance backed by President Emmanuel Macron ranked second with 161 to 169 seats, while the far-right National Rally (RN) party will get 135 to 143 seats.
The National Assembly has a total of 577 seats, and none of the three primary blocs are projected to get an absolute majority of 289 seats.
The first round was held on June 30, where 76 candidates were successfully elected, without needing a second round.
The RN got 29.26% of the vote by itself (37 seats), a rate that rose to over 33% when combined with its allies.
The NPF got 28.06% (32 seats) and Together for the Republic finished third with slightly over 20.04% (two seats).
Macron dissolved parliament and announced early elections after the RN swept more than 31% of the vote in the European Parliament elections on June 9, defeating his centrist bloc.
