German labor union Verdi asked Amazon.com Inc. workers in the country to stage a strike at two of the company's logistics centers as part of the group's ongoing demand for higher pay and better working conditions, Reuters reported Dec. 17.

The group asked employees to hold a strike at an Amazon warehouse in Werne on Dec. 17 and continue through Christmas Day at another warehouse in Leipzig, the newswire said.

The report said the union has been holding strikes since 2013 in an attempt to convince the e-retailer to pay warehouse workers as retail staff, in accordance with collective bargaining agreements in the country's retail and mail order sector. Amazon has repeatedly turned down the demands as it believes the employees' salaries should be in line with its rivals in the logistics industry, Reuters reported.

Workers in Germany, Amazon's second-biggest market after the U.S., already staged a protest during the Black Friday shopping sale event, but Amazon said the strike did not disrupt its operations.