Germany faces a broader wave of transport disruption after the GDL train drivers’ union announced strikes in a bid to push through higher wages and shorter working hours, with actions set to stretch over three days at its passenger operations and four days at its cargo unit.

Union members may strike between 2 a.m. local time on Jan. 10 through 6 p.m. on Jan. 12 at the passenger operations, the Gewerkschaft Deutscher Lokomotivführer said Sunday in a statement. Strikes at the cargo operations are supposed to start at 6 p.m. on Jan. 9.

German rail passengers have been hit with widespread delays and cancellations in recent months as the GDL called on its members to stop operating both passenger and freight trains on some days.

Train operator Deutsche Bahn AG said at the time of the most recent strike in December that millions of passengers were affected and urged people to avoid or postpone travel if possible. It also warned of “massive restrictions for industry and business” due to the impact on freight operations.

On Sunday, Deutsche Bahn slammed GDL in a statement and said it will seek a provisional injunction at the Frankfurt labor court to stop the planned walkouts this week.

Germany’s state-backed rail operator, under fire for frequent cancellations and delays, has embarked on a modernization of the nation’s busiest routes by 2030 with more than €80 billion ($87.6 billion) in government funding.

Almost all GDL members backed the option to escalate the wage dispute by going on strike if needed for unlimited periods of time. GDL’s previous walkouts were usually limited to one day.

The GDL union represents some 40,000 employees at Deutsche Bahn and other transport providers, according to its website. It holds significant sway as its members include many train drivers critical for operations.

Germany’s main railway union — Eisenbahn-und Verkehrsgewerkschaft, or EVG — has about four times as many members and represents train drivers and service and administrative staff.

Christiane Benner, the new chairwoman of Germany’s largest and most powerful labor union IG Metall, criticized the GDL in November in an interview with Bild am Sonntag.

She accused it of a lack of solidarity with the main EVG union and of creating an “unnecessary division” in talks with Deutsche Bahn’s management.