PRAGUE -- A gunman shot dead six people on Tuesday at a hospital waiting room in the eastern Czech city of Ostrava in an unexplained attack, authorities said.
It was the worst shooting in the Czech Republic since a man shot eight people dead at a restaurant in Uhersky Brod in 2015.
Police said they received calls about a shooting at 7:19 a.m. (0619 GMT) at the University Hospital in Ostrava, near the border with Poland, and officers were on the scene five minutes later. They were still searching for the assailant.
Police posted on Twitter a picture of a man they initially identified as a suspect but later clarified was a witness, saying they were also searching for another person.
Czech Television reported police led a man out of the hospital in handcuffs but did not confirm if he was a suspect.
Prime Minister Andrej Babis told the same broadcaster the shootings occurred at close range in the waiting room, while Health Minister Adam Vojtech said six people had died.
The hospital was evacuated and police were working to secure surrounding areas. Hamacek and Babis headed to Ostrava, 350 km (217 mi) east of the capital Prague.
There was no word on possible motivation for the attack.