Workers at Amazon sites across the world, including in the United States, Germany and France, were urged to strike on Black Friday, targeting the online retailer on one of the busiest shopping days of the year with calls for better pay.

The Make Amazon Pay initiative, which made the call for strikes, said industrial action was planned in more than 30 countries.

Germany's Verdi union said work stoppages were planned at 10 fulfilment centres in that country.

It demanded the company recognise collective bargaining agreements for the retail and mail order trade sector and called for a further collective agreement on good working conditions.

"As an employer, Amazon offers great pay, benefits and development opportunities - all in an attractive and safe working environment," a spokesperson for Amazon in Germany said in a statement.

Among other things, the spokesperson pointed to a wage increase for Amazon logistics employees in Germany from September, with the starting wage now at 13 euros ($13.52) per hour or more, including bonus payments.

On Friday morning, the company said the vast majority of its employees in Germany were working as normal, with strike action limited to nine of its 20 German fulfilment centres.

A spokesperson for Amazon France said there had been no sign of disruption to operations so far.

"This is the first time that Amazon has had an international strike day," said Monika Di Silvestre, Verdi's representative for Amazon workers.

"This is very important, because a major global corporation like Amazon cannot be confronted locally, regionally or nationally alone," she added.

(Reporting by Rachel More and Mathieu Rosemain; editing by Jason Neely and Mark Potter)