Ukrainian authorities have opened a terrorism investigation after a gunman killed six people and wounded at least 15 others in a brutal shooting spree that ended in a hostage standoff inside a Kyiv supermarket.

Officials say the attacker, a 58-year-old man born in Moscow who had been living in Ukraine, began his assault in the Holosiivskyi district of the capital. Armed with an automatic weapon, he moved along a residential street, shooting at passersby and killing four people at close range before forcing his way into a Velmart supermarket.

Inside the store, he shot and killed another victim and seized several hostages, triggering a tense 40-minute confrontation with security forces. Special forces eventually stormed the building, killing the gunman and rescuing four hostages, according to President Volodymyr Zelensky. Ukraine’s Attorney General Ruslan Kravchenko announced that the case is being treated as an act of terrorism, underscoring the gravity of the attack.

Interior Minister Ihor Klymenko described the assailant’s behavior as chaotic and indiscriminate, saying the man approached people one by one and fired at point-blank range. Among the wounded is a young boy born in 2015, who remains in hospital with gunshot injuries. His father and aunt were killed in the attack, while his mother is reported to be in serious condition.

The massacre has shaken a country more accustomed to front-line shelling than mass shootings in its cities. Incidents of this kind are rare in Ukraine’s modern history, and the attack has triggered a crisis of confidence in the police response.

National Police chief Ivan Vyhivskyi ordered an internal investigation after video emerged showing some officers retreating from the scene instead of confronting the gunman. The footage sparked public outrage and led to the resignation of Yevhen Zhukov, head of the Kyiv patrol police, who condemned the conduct of the officers involved as unprofessional and unworthy of their positions.

Investigators are exploring multiple possible motives. Authorities say the attacker had a criminal record, and his registered apartment was found on fire around the time of the shooting. Zelensky has demanded that every detail be examined, including how the man obtained and used a registered automatic weapon and whether his long residence in the eastern Donetsk region played any role in his radicalization or planning.