Brief warning strikes ahead of salary negotiations by Germany's largest union, Verdi, widely disrupted commuter transport and forced airlines to cancel many flights in Frankfurt, Munich and Düsseldorf on Tuesday. Lufthansa said stoppages by non-company baggage handlers and fire fighting crews had grounded 250 flights, Europe-wide. Idle buses and trams across southern Germany and in the Rhineland left many workers to find other ways to get to work. Ver.di wants a pay rise of more than three percent, saying public service wages have fallen behind commercial sector pay rates. Federal, state and local body governments insist on a nil pay round, citing empty coffers and dwindling tax revenues. Talks are due to resume on Wednesday.