Reporters donned their flak jackets as a precaution and were told by Marines to turn off the lights on their video cameras, CNN correspondent Rula Amin said.
And his impersonation of a cat at the weekend - when he purred contentedly out of actress Rula Lenska's hands - was greeted with derision from his opponents.
Labour Party London Assembly member John Biggs called Galloway, Respect party MP for Bethnal Green and Bow in east London, a "laughing stock" after he imitated a cat and pretended to lick cream from actress Rula Lenska's hands, as part of a task.