When his London-to-Washington flight was unexpectedly diverted to another city, it didn't occur to the singer once known as Cat Stevens that he was the problem. And when it finally did, he suddenly felt very vulnerable.
"I was literally cut off from my family, from my daughter. I was in the dark," the musician, now known as Yusuf Islam, told ABC News' Elizabeth Vargas.
Islam — who changed his name from Cat Stevens after he converted to Islam in the 1970s — was barred from entering the United States after his name was discovered on a U.S. government "no-fly" list on Sept. 21.
He said United Airlines' Flight 919 — from London to Washington's Dulles International Airport — seemed routine until he heard an announcement over the loudspeaker stating the plane would be landing in a different location. There were 249 passengers on board, and it never crossed Islam's mind that he might be the problem.
The flight had been diverted to Maine's Bangor International Airport, where federal agents were waiting.
"The door opened and in walked six gigantically tall, you know, uniformed officers, and they kind of came to me directly, and said, 'Are you Yusuf Islam?' And I thought, what is going on?" Islam said.
"They took me to the immigration office there. Then I got interviewed by some FBI agents, and that was like the beginning of what I began to realize was a terrible ordeal which I was about to go through," he said.
Islam, 56, said he was traveling to the United States with his 21-year-old daughter to record some music in Nashville, Tenn.
Now he wants to know why he's no longer allowed in the country where he had been welcome for so many years.
Islam says he didn't learn much from the questions he was asked by federal agents and said the questions seemed to revolve mostly around his Muslim name.
"Well, kind of how to spell my name, and they kept on repeating that question actually and saying, 'Are you sure you don't spell it Y-O-U-S?'
I said, 'no, I spell it Y-U-S-U-F' so I thought at one point, well hang on, they've probably got me wrong, mixed up with somebody else," Islam said.
"The questioning, you know, was just so strange and I just didn't know what was happening," he said.
Homeland Security spokesman Brian Doyle said only that Islam is on the no-fly list because the intelligence community has recently obtained information that "further heightens concern" about the folk singer.
"Yusuf Islam has been placed on the watch lists because of activities that could potentially be related to terrorism," Doyle said. "It's a serious matter."
Islam says he still doesn't understand why his new name has been linked to terrorism. In a statement, Islam says he's "initiated a legal process" to try to find out exactly why he was put on the list and removed from the flight.
United and the U.S. government have said that they're working to figure out why Islam was allowed to board the flight in the first place. Homeland Security officials have said they're looking at the possibility that Islam's name was spelled differently on the no-fly list.
Under rules imposed following the Sept. 11, 2001, attacks, once an international flight is bound for the United States, passenger information is forwarded to U.S. officials. The information is used to run a more thorough check against government watch lists. Authorities discovered Islam was on Flight 919 after receiving the passenger information from United.