At least 15 people were killed Thursday after a blaze tore through a nursing home in the eastern Ukrainian city of Kharkiv.

The fire broke out on the second floor of the care home in the ex-Soviet republic, which is one of the poorest countries in Europe.

President Volodymyr Zelensky described the incident as "a terrible tragedy" and said 33 people had been in the building when the fire broke out.

An AFP journalist at the scene saw smoke still billowing from one of the charred second floor windows as firefighters assessed the damage.

Zelensky confirmed the death toll of 15 reported by emergency services, adding: "We all pray that there will be no more."

It was not clear in the immediate aftermath of the fire how many of the survivors were taken to nearby medical facilities for treatment.

The emergency services reported nine people had been injured and five of them admitted to nearby hospitals, while Prosecutor General Iryna Venedyktova said 11 people were injured.

The emergency services said the fire was extinguished less than two hours after it broke out, adding that around 50 firefighters took part in the operation.

Venedyktova said the authorities were investigating the misuse of electric heaters as a possible cause of the blaze.

Firefighters work at the site of a fire in a nursing home in Kharkiv on January 21, 2021.
Firefighters work at the site of a fire in a nursing home in Kharkiv on January 21, 2021. State Emergency Service of Ukraine / Handout

The facility, called "Zolotoye Vremya" (Golden Time), is located among a clutch of low-rise buildings on the western outskirts of Ukraine's second largest city.

Ukrainian media cited the Kharkiv region's social protection department chief as saying Zolotoye Vremya was privately owned and had not been registered with government agencies as a residential home.

Kharkiv city authorities declared that Friday would be a day of mourning for those killed in the fire.

Ukraine's Interior Minister Arsen Avakov said in a statement that police were questioning the manager of the facility and three service personnel.

He added that police were also considering detaining the owner of the nursing home.

Ukraine's ombudsman Lyudmyla Denisova wrote on her Telegram channel that the facility was home to people aged between 25 and 90.

Deadly fires are not uncommon in Ukraine, where compliance with safety regulations is poorly enforced and ageing infrastructure is badly maintained.

Seventeen people died in May 2016 when a makeshift home for elderly people outside the Ukrainian capital Kiev caught fire.

In December 2019, a fire killed 16 people and injured 30 others at a higher education institution in the Black Sea city of Odessa.

The director was later arrested on charges of negligence.