On the eve of international conference on climate, riot police clashed with hundreds of environmentalists who called for climate defense at the Republic square in the French capital on Sunday, according to local reports.

Picture taken on Nov. 29, 2015 shows some of the shoes on the Place de la Republique in downtown Paris, France, as part of a peaceful rally called by the NGO Avaaz "Paris sets off for climate", as an attempt to protest the French authorities' ban on public gatherings. [Photo/Xinhua]

Defying a ban of rallies imposed by a state of emergency, some masked demonstrators tried to poured into the Republic square chanting "State of emergency, police state. you do not remove our right to demonstrate."

Tension erupted after they threw projectiles at police officers who fired gas to disperse them, the reports added.

According to Paris prefect Michel Cadot, 100 people have been arrested but no causalities have been reported.

In the wake of the bloody wave of explosions and shootings which left 130 people dead on Nov. 13, France banned "massive marches planned in public places in Paris and other French cities".

To Laurent Fabius, the French Foreign Minister who chairs the international gathering to fight against climate change, Sunday's clashes ""reinforce the difficult taken decision to ban demonstrations."

Using emergency laws, police also put 24 green activists under house arrest suspected of planning violent protests ahead of the summit.

Earlier in the day, like thousands of others around the world, climate change protesters had formed a 2-kilometre human chain and covered the symbolic Republic square with thousands of shoes calling for concrete acts to limit climate deterioration.

A high-profile gathering on climate will kick off on Monday, here where officials aim to reach a global and binding agreement to limit global warming below 2 degrees Celsius.

It was reported that 150 top officials from across the world will attend the summit. About 50,000 visitors, including more than 3,000 journalists are expected to take part in the United Nations' 21st conference on climate, according to official data.