Train drivers staged a two-hour strike Thursday on the Berlin and Hamburg commuter networks, part of an increasingly bitter pay dispute that has seen courts bar walkouts elsewhere on Germany's railway system, AP reported. The GDL union launched the walkout at 8 a.m. (0600GMT), with drivers taking their trains to the nearest station before walking off the job. GDL is seeking a pay increase of up to 31 percent for its members, and has rejected a 4.5 percent raise that railway operator Deutsche Bahn AG agreed to last month in talks with two other unions that represent rail employees. It wants a separate agreement for drivers, a demand the railway rejects. GDL says the drivers currently earn some ¤1,500 (US$2,050) per month after taxes, a figure it calls inadequate. It and other unions also have pointed to healthy earnings at Deutsche Bahn, which is preparing for partial privatization next year. The union announced the strike against commuter trains late Wednesday, after a labor court issued an injunction halting its original plan to target freight trains for a four-hour stoppage on Thursday. GDL has appealed that ruling. Deutsche Bahn also obtained court rulings preventing strikes on long-distance passenger trains and on local and regional trains outside Berlin and Hamburg. «This is the measure that is available to us,» the union's deputy chairman, Claus Weselsky, said of Thursday's strike on ARD television. «We want to send a clear signal,» he added. «The drivers' patience is at an end.» Deutsche Bahn managed to run only occasional commuter trains with non-GDL drivers during the two-hour stoppage, but the fallout was limited _ with many commuters on vacation and others either traveling before the strike started or using alternative train and subway lines. Both sides say they are open to mediation, but it remains unclear who might be brought in to calm the dispute, which has seen the two sides exchange a slew of litigation.