Under the Public Order Act 1986, the offence of violent disorder requires the presence of three or more persons using or threatening unlawful violence. The behaviour of the group taken collectively must be such as would cause a person of reasonable firmness present at the scene to fear for their personal safety. Since Brian and Andy were only two individuals, they cannot be charged with violent disorder under this provision. 

Key Point: Violent disorder under the Public Order Act 1986 requires a minimum of three individuals acting together with unlawful violence or threatening violence. This collective behaviour must create fear for personal safety in a reasonable person.