A 24-year-old Polish gunman who killed six people and injured more than 15 people on Saturday in Kraków has died in a hospital following multiple surgeries.

He opened fire at Kraków’s Main Market Square from a moving vehicle, killing four women and two men before the police could stop him.

Of the six casualties, one man was a British citizen, and one woman was an Austrian national. Citizens from Britain, Germany, Portugal and Russia were among those wounded in the shooting.

The police raced to the shooting scene and subdued him with bullets, but the assailant continued firing his weapon in his injured state before he collapsed.

He was taken to a hospital where he remained in a critical condition after multiple surgeries. He died around 4:30 a.m. on Monday, the Polish government said.

Eryk Stasielak, who works at the national prosecutor’s office in Krakow, said officers were working to determine the motive and find out other accomplices, if any at all.

“We are first of all investigating if he was inspired by anyone, if someone helped him,” Mr Stasielak told the AP. “We have secured his electronic devices, and we will try to open them and get to the contents.”

Two police officers were injured during the exchange of fire that weakened the assailant and landed him in a hospital.

Police also found three corpses, two women and a man, at the suspect’s residence in Ostrowiec Swietokrzyski. They identified the bodies as the mother, sister and father of the attacker.

Polish authorities say the suspect, Michal O, was “influenced by the far-right ideology” to kill people.

“Everything points to the fact that the shooter was influenced by far-right ideology, a matter that will also be subject to investigation,” Interior Minister Marcin Kierwinski said at a news briefing.