Ukraine has fired UK-supplied Storm Shadow missiles into Russia for the first time, British media reported Wednesday, after being given the green light from London.
Several missiles were launched against at least one Russian military target, The Financial Times said, citing an unidentified Western official.
The Times said government sources had confirmed the use of the long-range missiles for the first time.
The Guardian said Britain had given Ukraine permission to use the missiles in Russia in response to Moscow's deployment of North Korean troops on the border.
Russian pro-Kremlin military bloggers wrote that around a dozen Storm Shadow missiles were fired on a target in the Kursk border region, which is partially held by Ukrainian forces.
Ukrainian media posted aerial video footage from a drone showing a series of explosions at what appears to be a country estate, naming the location as Maryino, where the presidential administration has a sanatorium.
Ukrainian media reported the strikes could have targeted an underground military command centre.
Neither Moscow nor Kyiv have officially confirmed the missile attack or the use of Storm Shadows.
The reported attack came after Washington this week said it had cleared Ukraine to use its ATACMS against military targets inside Russia -- a long-standing Ukrainian request.
Russia said Tuesday that the missiles had been used to target a military facility in the Bryansk border region.
The reported strikes came as Moscow looks to retaliate against Ukraine for firing US-supplied long-range missiles on Russian territory for the first time and with the Kremlin accusing outgoing US President Joe Biden of dragging out the war.
Russia has ramped up deadly missile strikes in recent days, targeting residential areas and Ukraine's energy grid. Air alerts blare out across the country daily.
The United States said Wednesday morning that it was shutting its Kyiv office to the public after having received "specific information of a potential significant air attack".
Canada, Greece, Hungary, Italy and Spain -- all NATO members -- followed suit.
The US Embassy said Wednesday evening that it would reopen Thursday, after having "temporarily modified operations" due to a warning of a "potential imminent air attack".
