A gunman shooting randomly from a car killed four women and two men in the main square of the southern Polish city of Krakow on Saturday, officials said, before police shot and arrested the suspect.
Fifteen others were wounded including two police officers who were hurt - one of them seriously - in a shootout with the suspect, who police said wore "military-style" clothes and had military weapons.
Krakow police said on X that the alleged gunman was a 24-year-old Polish citizen, adding: "The only known perpetrator of the incident is in police custody". They did not mention a motive for the shootings.
Police said they started to receive reports at around 3 p.m. (1400 GMT) that an assailant had opened fire from a car and had shot randomly at people in the square in Poland's second-largest city, a popular tourist destination.
Unverified footage shared on social media showed people fleeing the scene as shots rang out and police sirens blared. Other video showed two people lying on blood-spattered paving stones and bystanders trying to resuscitate them. A third person lay motionless on the ground nearby.
"I saw shots being fired from the driver's side window, and smoke was coming out. I ran to the police station in the main market square; when I burst inside, it was full of people hiding on the floor," a man who gave his name only as Konrad, and witnessed the shooting, told news website Interia.
A 67-year-old man called Julek told Reuters that he saw a dark car appear suddenly before the driver started shooting at a group of people and drove off.
"If we had been two minutes earlier, we might have been shot," he said.
Katarzyna Cislo, a local police spokesperson, said: "The shooter was wearing military-like clothes and used military weapons. Many ... weapons and ammunition were found in his vehicle too."
TUSK HEADS TO KRAKOW
Prime Minister Donald Tusk said on X he was being kept informed about the incident in the historic centre of Krakow, a UNESCO World Heritage Site. He later headed to Krakow from the capital Warsaw, a government spokesperson said.
President Karol Nawrocki said his thoughts were with the victims, those affected and their families.
Unverified footage on social media showed shooting in the Main Market Square as traditional horse-drawn carriages, popular with tourists, passed through or were parked nearby.
A man could be seen taking cover in one of the many restaurants and cafes that line the elegant square.
"Police officers in Krakow intervened, risking their own lives. They acted immediately. Thanks to their heroic conduct, the assailant was quickly apprehended," Interior Minister Marcin Kierwinski said on X.
"One officer sustained a gunshot wound, while another is in very critical condition with three gunshot wounds. Surgery is currently underway."
Expressions of shock and condolence flooded in from around Europe.
Ukrainian President Volodymyr Zelenskiy called the shooting "shocking". "On behalf of the Ukrainian people, and personally, I extend my sincere condolences to the families and loved ones of the victims," he wrote on X.
European foreign policy chief Kaja Kallas called it "a tragedy that will be felt far beyond Poland".

Russian strikes hit power facilities around Kyiv, damage major bridge
Heavy rains flood tents housing displaced Palestinians, aid shortages worsen
Qatar says its mediation efforts between US and Iran continue to prevent escalation
Pope Leo urges South America to bridge divides on Uruguay-Argentina border
Trump makes hardliner Stephen Miller his chief of staff after midterm defeat
