The Kremlin said on Friday that Russia's intelligence services were investigating a drone attack on the Russian city of Voronezh, which it blamed on Ukraine.
Kremlin spokesman Dmitry Peskov said the security services were working to clarify details of the incident.
The regional governor said earlier on Friday that three people had been lightly wounded when a drone struck an apartment building in the city, about 180 km (110 miles) from the border with Ukraine.
There was no immediate comment on the episode from Ukraine.
