Russia’s Ministry of Defense has said it has identified the source of a strike that damaged buildings at the Kyiv-Pechersk Lavra complex in Ukraine’s capital.

A missile fired from a US-made Patriot air defense system was responsible for hitting the site. The statement claims the incident was the result of a malfunction within the system, The Caspian Post reports via TASS.

Russian officials further suggested that one possible reason for the alleged failure could be the transfer of air defense missiles with expired service life from Western countries to Ukraine.

“According to confirmed data, the complex of buildings of the Kyiv-Pechersk Lavra was struck by a missile of the American Patriot anti-aircraft missile system. One of the reasons for the incorrect operation of this system could be that Western countries supplied the Kyiv regime with missiles with expired shelf life,” the ministry said.

The claims have not been independently verified, and Ukraine has not issued a public response regarding the statement.