An Irish bar owner in New York who hung an American flag outside his pub to celebrate his new U.S. citizenship was devastated after an unidentified man burnt the flag in the early morning hours after July 4th.

John Doherty at the Playwright Pub on 35th Street in Manhattan, one of New York’s best known Irish taverns, says he was deeply shocked by what happened.

“I didn’t think anyone would touch the flag, especially on the Fourth of July,” Doherty  told The New York Daily News. “It’s disgusting that someone would burn it, flying that flag is part of being proud to be American.”

The unidentified man is seen on video tape approaching the U.S.  flag with his lighter and making repeated efforts to set it ablaze before he finally succeeds.

He stands by and admires his handiwork smoking a cigarette before wandering off.

The fire takes hold but eventually a fire brigade unit arrives to douse it thereby saving the building.

Police are now hunting for the arsonist who could have caused a major conflagration. Doherty suspects the man is from a rival restaurant.

Doherty had hung the flag to celebrate his achievement of becoming an American citizen just four days earlier.

The 18 minute video tape shows that numerous passers by did nothing to stop or report the flag burning incident.

Here’s the CCTV footage of the incident: