12:45 PM PT -- According to a police report obtained by TMZ ... Arana became loud and disorderly -- demanding to know why his friend (Hesny) had been arrested. Police say Arana "took a fighting stance and clinged (sic) his fist" and resisted arrest until officers put him on the ground and "delivered numerous knee strikes" to Arana's ribs. The arresting officer also reported smelling alcohol on Arana's breath.
What's still unclear -- why his pal Hesny was arrested in the first place.
Two of Justin Bieber's security goons were busted in Florida after allegedly attacking a cop TMZ has learned ... and for once Justin's got an airtight alibi.
We got video of bodyguards Hugo Hesny and Michael Arana leaving jail in Miami Sunday. Police confirmed the two were arrested Saturday night after a "Miami Meet Up" for Justin's new movie in Aventura, Florida.
The words "meet up" -- like the words "I'm retiring" -- are confusing, turns out JB himself was NOT in Florida -- he was up in Canada snowmobiling.
Details of the incident are sketchy ... but we know Hesny was arrested for battery on a law enforcement officer and his bail was set at $10.5K. Arana was popped for disorderly conduct and bail was set at $1,500.