The show of strength is believed to have been filmed in the Ardoyne area of North Belfast. Police have said they are investigating it after it appeared on social media.
“There can be no place in our society for masked gunmen and paramilitary shows of strength,” said Mr Lunn.
“Guns do not belong on the street and I know the vast majority of people in the area will be as disgusted by this incident as I am. If we are to have a truly shared future and united community, this sort of unacceptable display should be consigned to the past.
“If anyone has any information on this display, I encourage them to bring it to the police immediately.”