The 'Finesse' singer reportedly stopped singing during his Glasgow Green show in Glasgow, Scotland, before telling the audience he needed to leave the stage.
An source on the scene told ET that extinguishers were used to "put something out on stage".
A message appeared on the big screen above the stage which read: "This is a safety announcement. It is necessary to stop the show temporarily. Further information to follow."
Mars, 32, is currently traveling the world for his 24K Magic World Tour which saw him perform across Australia to sell-out crowds.