Jet2 has apologised to customers after a flight from Tenerife to Belfast International Airport was diverted due to "disruptive passengers".
The aircraft landed at Santiago de Compostela Airport so Spanish police could remove the two men.
The flight touched down in Belfast at 21:21 GMT on Saturday, almost three hours after its scheduled landing time.
A passenger said the men were warned repeatedly about being "abusive" to staff and others on the flight.
"They became aggressive towards other passengers," Drew Niblock told BBC News NI.
"They were issued with a verbal warning and a written warning, which they took absolutely no notice of."
He added: "They continued to be aggressive and threatening towards other passengers and indeed the cabin crew, to such an extent actually that one of the cabin crew was in tears."
Mr Niblock told BBC News NI that the cabin crew's decision to divert the plane was "the safest thing to do".
He said: "Passengers seemed to take it in good stead and I think everybody agreed that it was the right course of action that Jet2 had taken.
"From my perspective it was fine, but there were multiple children on board who I felt for.
"All the passengers took it in good faith, there didn't seem to be that many complaints and, as I say, I think the captain made the right choice."
The airline said it will assist with "any subsequent investigations and prosecute where necessary".
Jet2 added: "As a family-friendly airline, we take a zero tolerance approach towards disruptive behaviour."