PARIS - Thousands of protesters opposed to the French government’s plan to revamp the retirement system marched through Paris on Saturday, the 24th day of crippling strikes.

In an unusual gesture, unions organizing the march asked yellow vest protesters to join them. The march coincided with the 59th consecutive Saturday of marches by the yellow vest movement that seeks social and economic justice.

Brief scuffles marred the union march as individuals, some wearing masks, burned construction materials along the route. The march went from the Gare du Nord train station to Chatelet in central Paris.

“Whatever the color of the vest, we must stick together,” the leader of the hard-left CGT union Philippe Martinez said on BFMTV, referring to the several hundred yellow vests who joined the march.

President Emmanuel Macron wants to raise the retirement age from 62 to 64 and rid the complex system of 42 special categories, notably railway and bus and Metro employees, with their own rules.

The strikes have disrupted transport across France and beyond, hobbling Paris Metros and trains across the country as well as businesses. The strikes have been especially felt over the holiday season.

On Saturday, the SNCF train authority said only six of 10 high-speed trains were running. The Eurostar from Paris to London had four of five trains running. Paris Metro service was improving, with partial service on several lines that had been shut down from the start. Only two lines, both automatic, ran without problem.

Prime Minister Edouard Philippe plans to continue talks with unions after a holiday break. The unions plan a major day of action on Jan. 9.