Russian investigators reported Monday that strikes on civilian infrastructure in Ukraine’s separatist-controlled city of Donetsk killed at least five people, saying the attack was carried out by Kyiv’s military.

“On May 30, Ukrainian security forces shelled the center of the city of Donetsk. According to preliminary information, five civilians were killed, including a teenager born in 2009,” Russia’s Investigative Committee said as quoted by Russian news agencies.

It added 16 people were injured in the attack that damaged three schools.

Donetsk is the de-facto capital of the self-proclaimed Donetsk People’s Republic (DNR) in Ukraine’s eastern Donbas region that borders Russia.

Before sending troops into Ukraine, Russia recognized the independence of the DNR and neighboring Lugansk People’s Republic (LNR), another pro-Russian breakaway region.

Kyiv has been locked in conflict with Kremlin-backed separatists in the two breakaway regions since 2014.

Officials in the DNR stated on Telegram that the strike destroyed two housing blocks and three schools, accusing Kyiv of deploying artillery and cluster munitions.