Dramatic footage onboard the explosive-packed kamikaze sea drone shows the exact moment it struck the 4,754-ton Russian tanker in the Black Sea off the coast of annexed Crimea.

The engine room of the 463ft-long oil and chemical tanker was flooded and the vessel was forced to seek help, according to the audio of those onboard.

Members of the 11-strong crew suffered abrasions from shattered glass as the control room was partially destroyed.

Bright explosions could be seen from afar as the tanker - loaded with fuel - was hit.

In a humiliating blow to Putin, the attack came only a day after Russian warship Olenegorsky Gornyak was damaged following an almost identical Ukrainian sea drone attack.

According to sources from Ukraine's security service (SBU), Saturday's daring mission was again orchestrated jointly with the Ukrainian navy and 450kg of TNT explosives were involved, BBC reported.