Armed police and security forces stormed a Paris apartment this afternoon, after a man on a terrorist watch list blockaded himself inside.

Authorities say the man was "neutralised and detained" at around 1.00pm local time.

The raid comes a day after arrests were made in Belgium in connection to terror plots.

The man was inside an apartment located near a march in the French capital, which is expected to draw thousands of labour protesters.

Protesters are at the rally as part of a national day of action against plans to loosen protections for French workers.

Thousands of demonstrators are on the streets across the country to protest against government labour reforms, and they have been tightening their grip on France's fuel supplies.

Petrol stations are running dry, tankers are being held off the southern coast and not allowed to dock, the government is dipping into precious reserves and nuclear power capacity has been cut because workers have walked out.