Amazon said that 1,115 out of 23,000 workers had chosen not to come to work Monday at its logistics centers, including 14,000 temporary employees hired for the holiday season.
"The vast majority of our workers in Germany are not participating in these strike activities," Mary Osako, an Amazon spokeswoman, said in an email. "Amazon did not see any impact on customer shipments."
But the union Verdi claimed that a record number of workers had taken part in the strike and said further action was planned.
For the first time workers at Graben near Augsburg in Bavaria joined colleagues striking at Leipzig and Bad Hersfeld. The strike in Bad Hersfeld is set to continue until Thursday while Leipzig will strike until Friday.
Verdi spokesman Christoph Schmitz said: "We will have a lot of patience.”
Verdi said the number of workers striking on Monday was higher than Amazon’s figure and put it at 1,800 with 700 at Bad Hersfeld, 600 in Graben and 500 in Leipzig.
The union has been trying for months to bring the pay of Amazon's 9,000 workers in Germany in line with wages in the distribution sector.
Amazon refused, arguing that its distribution centers are logistics sites and that it pays its staff accordingly. Wages in the logistics sector in Germany are lower than in distribution.
Germany is Amazon's biggest market outside the United Sates but months of labour action, as well as a scathing TV documentary broadcast earlier this year, have tarnished the company's image.
In solidarity, US union activists joined a protest Monday outside Amazon's headquarters in Seattle, Washington state. About 50 people rallied in support of the striking German workers, Kathy Cummings, spokeswoman of the Washington State Labor Council, told AFP.
As problems accumulate in Germany, in October Amazon said it planned to open two distribution centres in the Czech Republic by the end of 2014.
The centers are a response to increased demand across Europe, Amazon said at the time, adding that it chose the Czech Republic for its prime location in the heart of Europe.