The head of Ukraine's patrol police, Yevhen Zhukov, has resigned after two of his officers faced criticism for allegedly fleeing a deadly mass shooting in the capital, Kyiv.

Six people died and 14 others were injured on Saturday after a man opened fire on people in the street in Kyiv's southern Holosiivskyi district before taking others hostage in a nearby supermarket. He was later killed in a shoot-out with police.

Footage has since been shared online appearing to show officers leaving civilians and running away from the scene.

Ukraine's Interior Minister Igor Klymenko said the officers in question had been suspended and that an investigation into their actions was under way.

"'Serve and protect' is not just a slogan. It must be supported by appropriate professional actions. Especially at critical moments, when people's lives depend on it," he wrote on Telegram.

However, Klymenko cautioned: "It is not entirely correct to make generalisations about the entire police only by the actions of two employees."

Zhukov told a news conference on Sunday that the officers had "failed to assess the situation properly and left civilians in danger". He also said they acted "unprofessionally and unworthily".

"As a combat officer, I have decided to submit my resignation from the position I currently hold," Zhukov said.

The Ukrainian authorities say they are treating Saturday' shooting as a terrorist act but have not yet spoken about a motive. Klymenko described the man's mental state as "clearly unstable".

Eight people remain in hospital, of whom one adult was in an "extremely serious condition" and three were in a serious condition, officials said.

Ukraine's President Volodymyr Zelensky said in an update on Sunday that the two officers had been "at the scene of the crime, but did not stop the murderer, and fled on their own".

He accused them of "inaction" and said a criminal case into the matter - which will also check their previous work - was being handled by Ukraine's national investigations bureau.

"We are going through a war and every day, unfortunately, there are human losses from Russian strikes," Zelensky said. "It is especially painful to lose people like this, in an ordinary city, just on the street."

More details are beginning to emerge about the victims of the attack.

One man was the father of a child who was injured in the attack, Kravchenko said. Another of those who died was thought to be the boy's aunt.

The shooter has been identified as a 58-year-old man who was originally from the Russian capital, Moscow, but who had been living in the Holosiivskyi district in the lead-up to the shooting.

Prior to this, he had lived in the eastern Donetsk region - which is largely under Russian occupation and was subject to a separatist conflict prior to Moscow's full-scale invasion - Ukrainian officials said.

The gun he used was officially registered, according to officials. They are now investigating how he obtained the necessary documents to renew his licence.

While Kyiv is often subject to attacks during the ongoing war with Russia, shootings of this kind are rare in the city.

Klymenko said there would not be a mass check of gun owners following the shooting.

"I believe that people should have the right to armed self-defence," he added. "Especially after the experience when, at the beginning of the full-scale invasion, civilians received weapons for national resistance."

Ukrainian citizens are permitted to own non-automatic firearms provided they meet licence conditions, such as not having a criminal record or history of mental illness.

Since the start of Russia's full-scale invasion in 2022, Ukrainians have been able to carry weapons for self-defence and to defend their country.

A 2023 small arms survey suggested that only around 3.4% of Ukrainian adults owned their own gun.