It is unclear how Ukraine succeeded in shooting down the command planes flying above the Sea of Azov

Ukraine’s military has shot down two of Russia’s command planes, in one of the most disastrous days for the Kremlin’s air power since the start of Vladimir Putin’s full-scale invasion.

Valerii Zaluzhnyi, Ukraine’s commander in chief, said his air force had destroyed an A-50 long-range radar detection aircraft and an Il-22 control centre plane. Both were flying above the Sea of Azov on Sunday when they were hit at 9.10pm local time.

The A-50, which detects air defences and coordinates targets for Russian jets, crashed instantly, killing its crew. The badly damaged Il-22 appears to have made an emergency landing at an airfield in Anapa, Russia.

It is unclear how Ukraine managed to target and shoot down the planes. One theory is that a Patriot anti-aircraft missile battery – supplied by the US – was used. This, however, would involve moving the system close to the frontline where it could be detected.