Union leaders say the strikes could go on for weeks

An estimated 20,000 local and regional authority staff including nurses, cooks and cleaners have joined the largest public sector strike in 14 years.

They are protesting against plans to extend weekly working hours by 90 minutes, from 38.5 to 40 hours a week.

Their union, Verdi, has said the longer hours would be used to cut jobs.

'Private households'

The industrial action, which originally started in the southern state of Baden-Wuerttemburg, has now spread to 10 of Germany's 16 states, including Bavaria, Saarland and Schleswig-Holstein.

Leaders at Verdi - Germany's biggest union with 2.4 million members - have warned that the strikes could last for up to six weeks.

"The strike will last until employers realise they can't simply dictate to employees how long they have to work," said Verdi chief Frank Bsirske.

However, analysts said that the strikes would not have a large economic effect. "It tends to be private households who suffer from this sort of strike," Eckart Tuchtfeld of Commerzbank explained.