According to union sources, hundreds of employees of several Berlin hospital operators went on strike early Monday morning. The warning strike began with the early shift at 5:30 am, said Verdi union secretary Max Manzey on Monday. The pickets gathered in front of the participating hospitals. Manzey spoke of an estimated 1,000 participants at Charité, the state-owned hospital group Vivantes and the Jewish Hospital. The walkout is expected to continue on Tuesday. An emergency service should be ensured.