China's commerce ministry said on Wednesday that it had urged Britain to stop sanctioning Chinese firms after the country sanctioned five Chinese companies over their links to Russia.

In a statement, the ministry said China "firmly opposes Britain's actions on the grounds that the Chinese companies are "related to Russia."

Britain last week imposed its first sanctions targeting vessels in Russian President Vladimir Putin's "shadow fleet" that it said was used to circumvent Western sanctions on the trade in Russian oil.

The action, part of 50 new sanctions and coordinated with G7 partners, also targeted suppliers of munitions, machine tools, microelectronics, and logistics to Russia's military, including entities based in China, Israel, Kyrgyzstan and Turkey, the British government said.

Britain's approach has ignored China's representations and the momentum and had a negative impact on economic and trade relations between China and the UK, China's commerce ministry said.

"Britain's approach is a unilateral sanction that has no basis in international law," it added. "We urge Britain to immediately correct its erroneous practices."