Xbox UK communicated news of the stunt via Twitter, stating: "Master Chief and Agent Locke have landed in London to celebrate the arrival of #Halo5".
A series of explosions were seen and heard nearby The O2, at which point a Covenant Banshee, a replica space ship from the game, could be spotted nearby the building following a crash landing.
Master Chief disembarked from his sleek mode of transport and began to walk away, at which point it exploded into flames.
He was then met by Agent Locke, who also appears to have just landed at the site in a Banshee, and the stunt ends with the two in a confrontational stance, surrounded by flames, with weaponry in hand.
The stunt took place in the lead up to the launch event at the Roundhouse in London last night (26 October), which was live streamed. The game, which is compatible with Xbox One, is available for purchase from today (27 October).
Last month Xbox opted for a racing car stunt to promote the launch of its Forza Motorsport 6 game. The brand took four YouTube stars down to the Top Gear test track for a one-off experience with the Stig.