German rail operator Deutsche Bahn said GDL, the union of engine drivers in Germany, began the part of its strike affecting passenger trains at 2 a.m. local time (0000 UTC) Wednesday.

"It has started," a spokeswoman for Deutsche Bahn said. There was no immediate information about pending negotiations, but a Bahn representative said discussions had been held in Frankfurt about possible arbitration. The talks were due to be "continued shortly," a spokeswoman said.

The union had already halted operations for freight trains Tuesday at 3 p.m. local time.

Deutsche Bahn (DB) was meanwhile working on an emergency travel plan to keep schedules as normal as possible over the Pentecost holiday.

The GDL union has not disclosed how long the strike will last but says it will let passengers know 48 hours in advance of the end of the walkout. It also said the strike would be longer than its previous action earlier this month, which lasted six days.

Second union involved

The union, which represents some 20,000 train drivers, is demanding a 5-percent pay hike for drivers, a two-hour cut in drivers' working week as well as the right to represent other rail workers such as conductors and restaurant carriage staff.

GDL accuses DB of not taking discussions on employees' salaries seriously and says the railway company is deliberately delaying an agreement because of a pending bill on equal salary packages in the German parliament. The larger railway union EVG has also threatened to stop work if its demands are not met.

The current strike is GDL's ninth since negotiations failed with DB last year, and the third such strike in 2015.

The strike earlier this month may have cost the German economy 755 million euros ($855.7 million). This week's walkout could result in a 500 million euro ($565 million) loss for German companies, Eric Schweitzer, head of Germany's DIHK Chambers of Commerce, told the media.

rc/cmk (AFP, Reuters, dpa)