Vladimir Putin has suffered a humilating blow after Ukraine struck his £120million warship in a huge attack near St Petersburg. The corvette Boykiy was hit in Kronstadt – headquarters of the Kremlin’s Baltic Fleet. The vessel was seen engulfed in flames in a Ukrainian video.

The 343ft-long vessel was like a “sitting duck” despite promises that defences had been tightened this week due to the St. Petersburg International Economic Forum [SPIEF], hosted by the Russian dictator. One year ago, the Boykiy was guarding Putin’s sanctions-busting shadow fleet through the English Channel.

The Steregushchy-class corvette was hit while in dry dock in naval base Kronstadt some 700 miles from the nearest Ukrainian territory.

It is a Project 20380 corvette, in service with the Russian Baltic Fleet since 2013 and equipped with guided missile weapons.

The Ukrainians also staged a major assault on the St Petersburg Oil Terminal, one of Russia’s most important Baltic Sea fuel-export hubs, handling millions of tonnes of petroleum products each year through rail-fed storage tanks and sea-tanker berths in the city’s main port. Putin is due to address the economic forum with a keynote speech on supposed “stability” in Russia despite the war.

Yet his second city – where Putin was born when it was known as Leningrad – was shrouded in noxious black smoke from the Ukrainian strikes.

At the forum St Petersburg is being touted as “the capital of unmanned technologies”. Two of Putin’s daughters were also due to address the forum.

Russia has not commented on the damage to the warship. It is unclear if there is further damage at the Kronstadt naval base or other ships. Earlier it was suggested up to four warships may have been hit.