There was more strife between Fiat workers and management in Italy on Thursday.

According to Reuters, groups of Fiat staff in Turin downed tools for four hours, demanding the Italian industrial group invest more money in the Mirafiori factory.

Unions reportedly said half the workers on the night shift had walked out for four hours, while 80% had observed the strike during the morning shift – Fiat reportedly said 18% of night workers and 33% on the morning shift had stopped work.

The news agency noted that unions have long worried that Fiat will turn its back on the Mirafiori plant, shifting production to more efficient and cheaper plants elsewhere in Italy or abroad.

Fiat has been hit by a series of strikes over the last few years as it slashes costs to pull itself out of deep losses, Reuters added.