German train drivers have begun a four-day strike in a bitter dispute with the country's national railway operator, causing chaos for commuters and raising concerns of short-term shortages.

Railway operator Deutsche Bahn said Thursday it was seeking a court order to stop the walkout by the GDL union, which it plans to run through Monday morning.

Meantime, the dpa news agency reported that experts were warning the increased number of cars on the road, coupled fuel delivery delays, could lead to shortages at service stations. Industrial production delays were also anticipated as companies await deliveries of components.

GDL wants a 5 percent pay increase and shorter working hours but the main sticking point is its demand to negotiate not just for train drivers but for other staff.