Workers at German warehouses of online retailer Amazon.com extended strikes as labour union Verdi pressed its demands in a long-running dispute over pay and conditions. Verdi said in a statement it had called out workers to strike at distribution centres in Bad Hersfeld and Graben after more than 600 staff walked off the job in Bad Hersfeld and Leipzig. The U.S. company employs a total of 9,000 warehouse staff at nine distribution centres in Germany, its second-biggest market behind the United States, plus 14,000 seasonal workers. Verdi wants Amazon to raise pay for workers at its distribution centres in accordance with collective bargaining agreements across the mail order and retail industry in Germany and has organised several stoppages over the past year. Amazon, however, has rejected the demand, arguing that it regards warehouse staff as logistics workers and says they receive above-average pay by the standards of that industry. Verdi said retail and mail order workers had a pay rise of 5.1 percent in two stages last year, while Amazon employees received an average raise of 2 percent. (Reuters)