BERLIN -- Workers at two Amazon distribution centres in Germany have gone on strike as part of a push for improved work conditions, leading to fears that Christmas orders may not arrive in time.

The German news agency dpa reported that workers in Leipzig in eastern Germany and Werne in western Germany went on strike early Monday.

The ver.di union representing the workers says Amazon employees receive lower wages than others in retail and mail-order jobs in Germany.

Amazon has said in the past that its employees earn relatively high wages for the industry.

The company said Monday that the "overwhelming majority" of its employees were working normally and that the strike at the two facilities in Germany would not affect its delivery commitments.

"We are well prepared for Christmas and look forward to delivering for our customers during this busy period, as we do all year round," Amazon said.