Russian attack helicopters have destroyed a convoy of Ukraine's armoured vehicles and anti-aircraft warfare, the news agency Interfax reported on Sunday, citing Russia's defence ministry.

"Attack helicopters KA-52 ... destroyed weapons and military equipment of the armed forces of Ukraine," the agency cited the ministry as saying in a statement.

Ukrainian military officials were not immediately available for comment. Reuters was not immediately able to verify the report.

The news agency said the ministry published video footage of attack KA-52 helicopters flying at extremely low altitude, launching missiles and firing from guns at ground targets.

The location and the timing of the attack was not specified.

(Reporting by Lidia Kelly; Editing by Robert Birsel)