Union activists are burning tires and blocking a major bridge on the northern French coast on a day of nationwide strikes and protests over a labor reform.

Demonstrators gathered early Thursday morning at a central square in the venerable port town of Harfleur, setting off fireworks and air horns.

Activists were unapologetic about the disruption they planned.

"We have to hit where it hurts," said union official Gilles Guyomard. "And where it hurts is the bosses' wallets."

The activists then went to the 2-kilometer-long Pont de Normandie, which bridges the Seine River at Le Havre, setting a pile of tires aflame and blocking toll booths.

Strikes and protests are being held around France on Thursday against a labor bill that extends the work week and makes layoffs easier.