PARIS (AFP) - Several hundred masked protesters hurled objects at police on Tuesday (June 14) during a demonstration in Paris against a contested reform of French labour laws, authorities said.

Police said they had made six arrests during the clashes, the latest such demonstration to turn violent since protests against the reforms began in March.

Demonstrators stormed a building site, taking wooden palettes and then throwing them at riot police, Paris authorities said.

At least two people sustained injuries in the clashes, according to an AFP journalist at the scene.

Authorities appealed to protesters to separate themselves from troublemakers to allow police to intervene.

Several demonstrations against the hotly disputed series of labour market reforms have previously turned violent.

However, the international spotlight is especially on France, the host of the Euro 2016 football championships.

In addition to violent demonstrations, overstretched French authorities are having to deal with football-related clashes and a heightened threat of terrorism during the tournament.

Terrorism fears came back to the fore after a man who claimed allegiance to the Islamic State in Iraq and Syria (ISIS) extremist group killed a police officer and his partner in a northwestern Paris suburb late Monday.