Some 10,000 workers at German carmaker Daimler AG walked off their shifts for an hour on Tuesday as they sought to persuade employers to give engineering workers around Germany more pay and a shorter working week.
Some 4,000 employees at other companies in the southwestern state of Baden-Wuerttemberg took part in strikes on Tuesday and further warning strikes are due on Wednesday at other companies, including at domestic appliance maker Miele.
With Europe's largest economy steaming ahead and unemployment at a record low, IG Metall - Germany's biggest trade union - is calling for a 6 percent pay increase for around 3.9 million workers in the metal and engineering sectors, including the car industry.
"The economy is booming because the employees like those here at Daimler do good work every day," regional IG Metall head Roman Zitzelsberger said in a rally at the gates of Daimler's factory in the town of Sindelfingen, near Stuttgart.
"So 6 percent is appropriate and we won't be fobbed off with 2 percent," he said.
The union says workers should be able to cut their weekly hours to 28 from 35 if they need to care for children, elderly or sick relatives and have the right to return to work full time after two years.
Employers reject the demands to cut hours unless working time could be increased temporarily as well. They argue that workers in Germany's industrial sector already have shorter weeks than their peers in other countries and worry that reducing their hours further would hurt German competitiveness.
IG Metall said more than 376,000 employees in the engineering sector had gone on warning strikes so far this year since a non-strike period ended on Dec. 31.