Seven people, including three children, were killed in a Russian drone attack on a gas station in the Ukrainian city of Kharkiv on Saturday, regional authorities said.

The victims included two children aged seven and four, as well as a six-month-old child, Kharkiv region Governor Oleg Synegubov said on the messaging app Telegram. 

An Iranian-made ‘Shahed’ drone hit civilian infrastructure in the Nemyshlyan district of the city, causing a massive fire that burned down 15 private houses. Kharkiv is Ukraine’s second-largest city and is located in the northeast of the country.

‘Unfortunately, the death toll from the occupiers’ attacks on Kharkiv have risen to seven,’ Synegubov wrote. ‘The occupiers struck Kharkiv with ‘Shahed’ kamikaze drones.’ 

Synegubov said that the bodies of five people, including the three children, were found in a private house. The adults were the children’s parents, Syniehubov said.

Two more people – a couple aged 66 and 65 died at another facility, according to reports. ‘More than fifty people were saved!’ he wrote. 

The houses caught fire after three drones hit a petrol station in the Nemyshlianskyi district, according to the local prosecutor’s office in Kharkiv.

Video from the scene shows heavy flames ripping through buildings. 

Kharkiv regional prosecutor Oleksandr Filachkov said three drones hit Kharkiv’s Nemyshlyanskyi district.

‘As a result, a building for critical infrastructure was destroyed. There was a large amount of fuel, which is why the impacts of the fire were so terrible,’ Filachkov said in a video posted online.

The Ukrainian air force said air defense systems destroyed 23 out of 31 drones launched by Russia overnight. The drones primarily targeted the northeastern Kharkiv region and the southern province of Odesa, the statement said, according to the Associated Press.

Firefighters and rescuers worked through the night to cope with the consequences of the strike, extinguish fires and clear through the debris, officials said.

Russia has previously said that it does not deliberately target civilian sites.

The attacks came as the Russian invasion and ongoing conflict approached its second anniversary.

The Associated Press and Reuters contributed to this report.