The rally was held on Sunday despite a ban on all demonstrations under a state of emergency announced in the wake of recent terrorist attacks in the French capital.
The rally, which had been cancelled by authorities, was nevertheless held by some 10,000 people, who formed a three-kilometer human chain along the route of the demonstration.
While the gathering was mostly peaceful, clashes erupted in Place de la République Square when a number of masked demonstrators started hurling objects at police. The arrests were made during the clashes, Press TV reported.
A state of emergency has been in place in France ever since November 13, when a string of coordinated terrorist attacks killed some 130 people and injured 350 others in Paris.
The UN conference on climate change – dubbed COP21 – is due to be held amid heavy security in the French capital on Monday. The confab is hoped to produce a deal on cutting emissions that precipitate global warming.
Some 152 heads of state and government are due to attend the forum in Paris.