- The plane was already in the air when US officials identified that the singer, whose name is now Yusuf Islam, was on one of their "watch lists".
United Airlines Flight 919 was diverted 600 miles, landing in Maine.
After an interview, the singer - who converted to Islam in 1977 - was denied entry into the US.
Transportation Security Administration (TSA) officials said the access was denied "on national security grounds", without giving any further details.
Yusuf Islam is now expected to be put on a flight out of America later on Wednesday.
Four years ago, Mr Islam was deported from Israel over allegations that he backed militant Muslims. [BBC]
including advocating the murder of Salman Rushdie for heresy for the Satanic Verses, he has subsequently retracted that opinion.
I used to love the Cat, still love the music: he had an exceptional melodic gift, unique voice, and knack for blending folk, rock and pop into a amazing string of bright, deep songs, as demonstrated on his extraordinary The Very Best of Cat Stevens:
Matthew & Son
The First Cut is the Deepest
Where Do the Children Play?
Hard Headed Woman
Father and Son
Morning Has Broken
Damn! every single one of these (and more: "Angelsea") is a play-along, sing-along classic, with exceptional arrangements and production. The touch was fading in the later-'70s as he grew less focused and more eclectic-poppy, but he threw it ALL away when he went hard-core Muslim in '77, and not regualr old Western-style Muslim, but kill-the-infidel, lost-his-fucking-mind jihadi Islamist.
AP has more on the flight issue and his background:
- One official, speaking on condition of anonymity, said Islam, 56, was identified by the Advanced Passenger Information System, which requires airlines to send passenger information to Customs and Border Protection's National Targeting Center. The Transportation Security Administration then was contacted and requested that the plane land at the nearest airport, that official said.
Melendez said Islam was questioned by FBI and Immigration and Customs Enforcement officials.
Another federal official, who is in law enforcement and spoke anonymously because of agency policy, said that after the interview, Customs officials decided to deny Islam entry into the United States.
....He abandoned his music career in the late 1970s and changed his name after being persuaded by orthodox Muslim teachers that his lifestyle was forbidden by Islamic law. He later became a teacher and an advocate for his religion, founding a Muslim school in London in 1983.