An attacker shot dead six people sitting in a waiting room at a hospital in the northeastern Czech city of Ostrava on Tuesday, the government said.
Police said on Twitter they were still searching for the assailant and posted a picture of a suspect without giving a name. There was no word on possible motivation for the attack.
The shooting took place at the University Hospital in Ostrava soon after 7 am (0600 GMT), Interior Minister Jan Hamacek told Reuters.
Prime Minister Andrej Babis told Czech Television the shootings occurred at close range in the waiting room, while Health Minister Adam Vojtech said six people had died.
Hamacek and Babis were headed to Ostrava, 350 km (217 mi) east of the capital Prague.