A part of a 10-story apartment building collapsed in Russia's Belgorod on May 12, Governor Vyacheslav Gladkov reported.
Gladkov claimed without evidence that a building in the Kharkovskaya Gora district was hit by a Ukrainian projectile during an air raid alert in the oblast.
Later in the day, Reuters reported, citing its sources in Russia, that at least seven people were killed.
Russian air defenses allegedly shot down six Tochka-U missiles and six rockets over Belgorod Oblast, according to the Russian Defense Ministry. The ministry claimed that the residential building was "damaged" by a Tochka-U missile fragment.
Local officials did not report on casualties, while Russian state-run media claimed at least 20 were injured, citing response services.
There is a risk of further collapse of the building, the Kremlin-controlled news agency TASS wrote. Footage shared on Russian Telegram-channels soon after showed a section of the roof collapsed.
Ukrainian officials did not comment on the claims. The Kyiv Independent could not independently verify the reports.
Claims of rocket or drone attacks against Belgorod Oblast, which borders Ukraine's Sumy, Kharkiv, and Luhansk oblasts, have become a common occurrence in recent months.
Russia often uses Belgorod Oblast as a launching ground for cross-border missile strikes against Ukraine. Russian troops repeatedly attack residential buildings across Ukraine, killing and injuring dozens of civilians, including children.