Thousands took part in parades across the north to mark the Twelfth, which commemorates the 332nd anniversary of The Battle of The Boyne.
Footage circulating online appears to show loyalist members of a marching band dressed up in green Martian costumes as they walk in a parade to mark July 12th.
The video shared on Twitter captures the adults of the marching parade donning green Martian alien suits.
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The costume shows a green alien carrying each member on their back, as they move up the street playing their instruments, while onlookers record the bizarre antics.
The video has went viral and is captioned: “I’ve watched this about 20 times and still can’t believe it’s real.”
It’s unclear why the band chose to wear the green Martian costumes, but many have expressed confusion at their choice of attire.
The Twelfth (Orangemen's Day) sees members march as supporters line the streets as the annual Orange Order parades celebrate the Battle of the Boyne, when William of Orange - also known as King Billy - defeated the Catholic King James II in 1690.
In the footage, members of the band walk on as four children dressed in blue alien costumes lead the parade.
The night before the “11th night” sees bonfires lit across Northern Ireland, which is one of the busiest nights for the fire service.
On this night, large towering bonfires are lit.
Several viewers have been left in disbelief at the costumes worn by the band, and many took to the comments to share their thoughts wondering if the events were real.
One bewildered user said: “I need to know how this was made!!! Holy Halloween!!!”
A second said: “Please tell me someone mistyped/misheard during the organisation of this and they just ran with the idea of a "Martian" band instead.”
A third said: “Martian up the road so we are.”
While a shocked viewer said: “Thought I had been spiked with acid watching this”
Meanwhile an investigation has been opened into the death of a man who fell from a bonfire in Co Antrim.
John Steele, who was in his 30s, died on Saturday night following the accident in Larne.
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