Russian officials in occupied Berdiansk said Ukrainian forces have struck the city with a missile.
Ukraine's military "launched a massive strike" on the city, Vladimir Rogov, a member of Russia's local administration in Zaporizhzhia, posted on Telegram on Thursday.
Rogov said he still did not have information on casualties, adding that response teams were on site.
"It's not yet known whether British Storm Shadow missiles or something else was used," Rogov added.
If Ukraine was behind the alleged strike, the use of Storm Shadow missiles are a likely option, given Berdiansk is deep in Russian-controlled territory, around 100 kilometers (about 62 miles) from the front line.
About the missiles: The Storm Shadow is a long-range cruise missile with stealth capabilities, jointly developed by the UK and France, which is typically launched from the air. With a firing range in excess of 250 kilometers, or 155 miles, it is just short of the 185-mile range capability of the US-made surface-to-surface Army Tactical Missile Systems, or ATACMS, that Ukraine has long asked for. The United Kingdom said it delivered multiple of the Storm Shadow missiles to Ukraine earlier in May.