Date: 202101
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise; Parked
Airspace: Class A ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Detector: Person Flight Attendant
Result: Flight Crew Diverted; General Police / Security Involved
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Human Factors

Narrative: Pushed away from gate. Started taxing in ZZZ alley when I got a call from #1 Flight Attendant; (FA); that there were First Class; FC; passengers that were not wearing face coverings after being told to wear them by the FAs. Stopped the aircraft and made a very 'To the point' PA that any non-compliance with Flight Attendant instructions; particularly pertaining to facial coverings; would have 'un-favorable' consequences. I had already made it clear that facial coverings were required while on-board during my 'welcome aboard' PA. Conferred with FAs that my second PA was successful; and we continued taxi and takeoff. Once established in cruise; the FAs informed me that they were having problems with FC passengers willfully being non-compliant regarding wearing a facial covering after being advised as such multiple times by at least 2 different FAs. My FAs had even switched working positions in order to try to de-escalate the situation and convince the passengers to comply. I commenced communication with Dispatch and relayed the situation with advisement to contact customer representatives. Shortly thereafter; due not only to non-mask wearing; but also; disruptive behavior by passengers requested to be re-seated in Main Cabin. I further relayed this information to Dispatch. It was at this point the FAs gave the notification of passenger misconduct warning. Shortly thereafter passenger started harassing my FAs with constant cornering them in the FC galley and demanding trivial items. At this point; even after a tremendous amount of patience; de-escalation attempts and warnings by the FAs; and with building harassment and aggressiveness being demonstrated by passengers; I notified Dispatch that we would be diverting to ZZZ1. We landed at ZZZ1 non-eventfully; without being overweight and without declaring an emergency. Passengers were removed from the aircraft. We departed ZZZ1 and arrived in ZZZZ uneventfully. Please allow me to acknowledge my FAs for their display of 'Consummate Professionalism' during this flight. They were tireless in their attempts to de-escalate the situation in hopes of precluding a diversion. I would also like to acknowledge the support of Dispatch and company as reflective of the number of communications that were made prior to our diversion. And last; but certainly not least; I would like to acknowledge the expert airmanship demonstrated by my First Officer during our extremely busy diversion as well as throughout the rest of a very long day. Should you need additional information from me regarding this diversion; please don't hesitate to contact me.




Synopsis: Air carrier Captain reported passengers were unruly and not complying with face mask policy despite multiple warnings by the crew resulting in a diversion; and removal of the passengers.