A disruptive passenger ended up bruised and embarrassed after initiating a fight on a Frontier Airlines flight.

Twenty-one-year-old Ishaan Sharma was removed from the plane and taken into custody for allegedly assaulting fellow passenger Keanu Evans without provocation.

The altercation began as the flight neared Miami-Dade International Airport from Philadelphia.

Ishaan, from New Jersey, is said to have grabbed Keanu, one seat behind him, by the throat.

He reportedly lashed out after muttering strange things and making death threats.

Evans told WSVN: “He was doing some, like, dark laugh like: ‘Ha ha ha ha ha.’

” And he was saying things like: ‘You punt, mortal man, if you challenge me, it will result in your death.'”

Ishaan allegedly attacked after Keanu pressed the assistance button to call for help from airline staff.

Footage posted online seems to show Ishaan standing over Keanu and gripping him by the throat.

But the tables quickly turned when Keanu stood up to defend himself.

He swung for Ishaan and landed a series of hefty blows on the instigator’s face.

Alarmed passengers can be heard shrieking: “Let him go! Stop, let him go.”

Later footage shows Ishaan grinning as he climbs out of his seat with a bib of sorts tied around his neck.

He strolls off the plane, bare-chested, with a smile still plastered across his face.

But the smirk was wiped off his face when he was arrested by cops inside the terminal.

His mugshot shows him sporting a gnarly shiner on his left eye and cuts across his face and neck.

Keanu later said: “What I hate is that the video doesn’t capture what started the whole thing, you know?

“It only captures me defending myself.

“It makes me feel bad because I don’t want people to get the wrong idea about who I am as a person.”

Ishaan was taken into custody at Miami-Dade and is charged with battery, according to the sheriff’s office.

His defence attorneys claim he had been “meditating” and that Evans was somehow upset by that.

Renee Gordon said: “My client is from a religion where he was meditating. Unfortunately, the passenger behind him did not like that.”