A German train drivers' union says they will stage another strike after talks with the country's main railway operator over the weekend failed to produce an agreement.

The GDL union said Monday that freight train drivers would go on strike Tuesday and passenger train drivers would follow Wednesday, the dpa news agency reported.

Union head Claus Weselsky says the strike is not open-ended but gave no specific timing, saying it would be "somewhat longer" than the five-day walkout in May — the longest strike so far in an increasingly bitter dispute with the operator, Deutsche Bahn.

GDL wants a 5 percent pay increase and shorter hours but the central sticking point is its demand to negotiate for other staff, including conductors, who are traditionally represented by a larger rival union.