Some six million Germans are facing difficult commutes after a small train drivers' union began an indefinite strike, paralyzing the country's rail network.

The GDL union gave no indication of how long the walkout, which started Wednesday, would last. It's affecting not only long-distance trains but also some parts of city subway systems.

It is the ninth strike in less than a year in a dispute over pay, working hours and GDL's right to negotiate for other railway employees.

Rail company Deutsche Bahn has rejected the demands and said it will try to provide a skeleton service on selected routes.

Germany's chamber of commerce says the nine strikes together could cost the country's economy 1 billion euros ($1.12 billion).