Poland declared two days of national mourning beginning Sunday, while police bolstered security nationwide following a mass shooting in Krakow that killed six people and was likely inspired by far-right ideology, authorities said.
Saturday's attack in the city's historic main square shocked a country that has prided itself on being safer than many of its Western European neighbors, deepening public concern following a string of school stabbings in October that officials linked to extremist content online.
Authorities said the attack wounded 17 people, including two police officers and the gunman.
Police and a local official said officers later found the 24-year-old suspect's parents and sister dead at their home. He remained in critical condition at a hospital.
In Krakow, police kept the Old Town's main market square and surrounding streets closed, allowing only essential workers to pass.
Many nearby cafes were closed and flags at the city hall flew at half-staff. Mourners placed candles in several locations in the area.
State news agency PAP reported authorities suspended the traditional trumpet call from St. Mary's Church on the square for 12 hours to commemorate the dead, the first time this had happened since 1939.
In the capital, Warsaw, police said Saturday they were strengthening security measures in busy areas popular with tourists.
Police installed barriers on streets leading onto Krakowskie Przedmiescie Street in the historic heart of the capital.
In the suspect's hometown, Ostrowiec Swietokrzyski, about 200 kilometers (124 miles) north of Krakow, police said they had found the bodies of his parents and sister and that investigations were underway.
"Yesterday, before 10 p.m., we discovered the bodies of three people – a 53-year-old man, a 52-year-old woman and a 21-year-old woman – in an apartment in a residential building in the center of Ostrowiec Swietokrzyski," police wrote on X.
Maria, a 20-year-old Warsaw cafe employee, said she "almost burst into tears” when she heard about the attack in Krakow.
"Recent events – not just this one, but things happening lately – are really affecting our sense of security," she said.
The daily Rzeczpospolita said in an editorial that the mass shooting brought a "brutal end to an era in which Poland was considered an island of safety."
Besides expressing shock at the killings, officials and members of the public praised the actions of police officers who arrested the gunman after a close-range shootout.
The shooting wounded two officers and police appealed urgently for blood for one officer who was "fighting for his life in a hospital."
"Senior Constable Jakub Kulik and Senior Constable Artur Moranski are true heroes," Prime Minister Donald Tusk said Saturday in a post on X. "They likely saved many lives, disregarding the risk to their own."