ODESA, Ukraine -- Six people have died as fire swept through a psychiatric hospital in Ukraine's Black Sea port of Odesa, authorities say.
Five people were hospitalized with carbon-monoxide poisoning after the fire erupted late on June 10 in the one-story building, Ukraine's Emergency Service said.
The dead included a nurse and five patients, according to an RFE/RL journalist.
The cause of the blaze was not immediately clear.
Police opened a criminal investigation into possible fire-safety violations.
Ukrainian President Volodymyr Zelenskiy said he regretted the "terrible tragedy" and directed Prime Minister Volodymyr Hroysman to immediately set up a commission to investigate.
Deadly fires are not uncommon in Ukraine due to outdated infrastructure and poor security measures.