A gunman opened fire in a nursing home in Croatia, killing at least six people, including his mother, in a rare instance of gun violence in the Balkan country, officials said.Five residents and one employee were dead after the gunman entered the private nursing home in Daruvar in north-east Croatia on Monday and began shooting, according to police.The gunman then fled the scene and was later arrested at a cafe, where he was carrying unregistered firearms.The man had a police record for disturbing public order and domestic abuse, said the Croatian national police chief, Nikola Milina.Officials first reported that five people had been killed during the shooting, but Milina confirmed a sixth victim died after being taken to hospital.Marin Pelić, the Croatian social policy minister, said: “This is an unprecedented crime.“According to the information we have, the mother of the killer had been in the nursing home for 10 years.”After the shooting, police sealed off the private nursing home located along a quiet street, where a small crowd gathered and watched as a forensics team entered the residence.Police said they were informed of the incident at 10.10am local time (8.10am GMT), and confirmed the suspect had entered the nursing home and used a firearm.Local media reports described the suspected shooter as a retired military police officer who had fought in Croatia’s war of independence during the breakup of Yugoslavia from 1991 to 1995.As news of the shooting spread, shock spread through Daruvar, a quiet town of about 7,000 people that has long been a popular spa destination thanks to the area’s thermal springs.Damir Lnenicek, the town’s mayor, told the N1 regional broadcaster: “It’s hard for me to understand that this can happen in our town, country.”About 20 people lived in the nursing home at the time of the shooting, Lnenicek said.“What is the trigger? It’s difficult to say, it will be determined by the investigation,” he added.After the shooting, Croatia’s president, Zoran Milanović, said the shooting “savage”.“It is a terrifying warning and a last call to all competent institutions to do more to prevent violence in society, including even more rigorous control of arms ownership,” he wrote on social media.Shootings in Croatia are rare, with Monday’s incident among the worst in the country’s history since independence was declared in 1991.Last year in neighbouring Serbia, the country was rocked by back-to-back mass shootings, including a massacre at a school in the capital in Belgrade in which 10 people were killed.