As police rushed to the scene, terrified patients desperately scrambled out of windows at the University Hospital Center in the capital Zagreb.

One female patient told local media: “We were in our rooms when the doctor came in, locked us inside, and told us that there was a man with a gun in the hospital.

“We waited in fear, and then about 20 of us decided to escape through the windows.”

When officers arrived on site, they found the man threatening staff and armed with a starting pistol used in sporting events.

After prolonged police negotiations the man eventually surrendered and was taken into custody for questioning.

Assistant director of the clinic, Dr. Milivoj Novak, said that no one was injured during the incident, adding: “The police responded promptly, and the area was quickly evacuated. Fortunately, no one was at risk during the standoff.”