A number of Amazon employees in Germany began a two-day strike on Thursday night in a fresh escalation of a long-running dispute over pay and conditions.

Employees at one of the online retail giant's German dispatch centres in the central town of Bad Hersfeld, Hesse stopped work in the early hours of Friday morning.

"The strike has been running [in Bad Hersfeld] since midnight," said a spokeswoman from public sector workers' union Verdi.

Workers at a second dispatch centre in Leipzig were due to stop work on Friday morning. 

The strikes are the latest in a dispute over pay and conditions which has been dragging on for over a year.