This is the moment a drunken vandal who had climbed onto a historic tram monument slipped from the roof and smashed his face into a metal fence post.

The incident occurred in the early hours of July 28 in St Petersburg, Russia, at the site of the 'Blockade Tram' memorial, dedicated to the 900-day siege of the city by Nazi forces during World War II.

Footage shows the 32-year-old man on top of the static display, which commemorates wartime public transport.

One man was seen filming while another stood on the tram's roof, kicking at parts of the structure.

Their rampage took a painful turn when one of the men lost his balance and fell head-first into a nearby railing, slamming his face against a metal post.

By the time police arrived around 7 am, two floodlights had been ripped out, a commemorative plaque had been damaged, and the tram's 'Route 12' sign was missing.

Three suspects were arrested later that day at their homes. Authorities confirmed they were intoxicated at the time and now face criminal charges for desecrating a monument considered a symbol of military honour.

Officials added that the footage recorded by one of the suspects is being used as evidence in the investigation.