A replica firearm was recovered from one of the men when specially trained officers with a police dog found and arrested the pair at the Westmount area.
The police are now looking for anyone who saw the two men acting suspiciously in the lead-up to the arrest.
They were first spotted outside the Grand Hotel at around 5.40 pm.
Police have stressed that the public were not in any danger, but have appealed for anyone who may have seen anything to get in touch.
A statement from the police said: “Although the matter was resolved quickly it is believed that there were a number of witnesses to the conduct of these males, including a male taxi driver, seen parking a white Toyota, in Pierson Road who briefly interacted with these males as he walked towards the nearby public toilets.
“Any witnesses to this incident are requested to contact Police Headquarters. This is an isolated incident and there is no concern for public safety.”
Anyone with any information can get in touch with the police on 612612.