Russia has warned of “consequences” following reports that British-built drones were deployed to hit targets on its mainland for the first time.

Ukrainian army sources told that drones made by two British companies have been used in the past six months to attack targets including oil refineries in Volgograd and near Moscow and logistics hubs.

Russia’s embassy to the UK said in a statement on Monday that the reports “confirm that London is deliberately opting for an escalation of the Ukraine crisis” and accused Britain of “seeking to contain Russia and inflict maximum damage on it by proxy”.

“London’s actions will inevitably carry consequences for which it will have to answer,” it added.

“The deeper its involvement in the conflict and the greater its support for Kyiv’s terrorist machinery, the higher the price it will pay.”

One drone was developed by BAE Systems subsidiary Callen-Lenz and tested by the Royal Navy.

The Nyran drone, which was built in Wiltshire, was used to strike Belgorod near the Russian border, the report published in said.

According to the defence company the drone can fly more than 150 miles.

“We deliver a range of capabilities into the UK MoD as part of the UK’s support to the defence of Ukraine,” the company confirmed to .

“The Nyan uncrewed air system provides a rapidly developed platform proven in meeting emerging threats within highly contested environments.”

There is a second drone made in British factories and used by the Ukrainian military, but the name of this company has not been revealed for security reasons.

It’s launched using a catapult system and has a range of more than 600 miles.

The UK has provided Ukraine with Storm Shadow missiles, but the supply is finite, and their range is only around 155 miles.

Former chancellor Rachel Reeves also confirmed a £752m payment to Ukraine earlier this year as part of a larger £3.36bn loan.

In April, the UK announced the biggest ever drone package for Ukraine, delivering at least 120,000 drones for Ukraine this year.

The package included thousands of long-range strike drones, intelligence and reconnaissance drones, logistics drones and maritime capabilities, which are all battle-proven on Ukraine’s frontline.

According to the Ministry of Defence the majority of this investment was set to be spent with UK-based companies, including Tekever, Windracers and Malloy Aeronautics.

However, British parts have also been found in Russian drones. Volodymyr Zelensky said microcomputers for flight control, manufactured in the UK, were discovered in drones involved in a deadly assault. Parts from other allied countries, including the US were also found.

He called for more stringent sanctions against British companies implicated in supplying components for Russian drones.