Moscow : In a statement, Russia's embassy in London accused Britain of becoming "an accomplice and co-perpetrator" of the attacks and of "deliberately opting for an escalation" in the conflict.

"Would Pay A Price": Moscow Warns UK After British-Made Drones Hit RussiaRussia's warning came after it reported that UK-based drones had been used against Russian territory.

Russia warned Britain on Monday it would pay a "price" after reports that UK-made drones supplied to Ukraine had been used in strikes deep inside Russia.

The warning came after the Sunday Times newspaper reported that drones produced by two British companies had been used by Kyiv to hit military and industrial targets inside Russian territory. 

In a statement, Russia's embassy in London accused Britain of becoming "an accomplice and co-perpetrator" of the attacks and of "deliberately opting for an escalation" in the conflict.

"The deeper its involvement in the conflict and the greater its support for Kiev's terrorist machinery, the higher the price it will pay," it said.

According to the Sunday Times, one of the companies involved is a subsidiary of defence giant BAE Systems.

The newspaper did not identify the second company, citing security reasons.

Britain's defence ministry did not immediately respond to a request for comment.

The UK has been one of Ukraine's strongest backers since Russia launched its full-scale invasion in February 2022, committing around 25 billion pounds ($33 billion) in support, including 16 billion pounds in military aid.

Ukraine has stepped up long-range strikes inside Russia in recent months, while Moscow has also intensified missile and drone attacks on the Ukrainian capital.