LONDON – The singer formerly known as Cat Stevens returned to Britain on Thursday, saying he was “totally shocked” that he was barred from entering the United States.

The singer, who changed his name to Yusuf Islam more than 25 years ago, was met by a swarm of reporters as he came through the arrivals area at Heathrow Airport.

“I’m totally shocked,” Islam said. “Half of me wants to smile, and half of me wants to growl. The whole thing is totally ridiculous.”

U.S. officials ordered Islam taken off a London-to-Washington flight on Tuesday, saying he was on a security watch list because of suspicions that he was associated with potential terrorists.

On his return to London Thursday, he appeared calm.

“Everybody knows who I am. I am no secret figure. Everybody knows my campaigning for charity, for peace. There’s got to be a whole lot of explanation,” he said.

British Foreign Secretary Jack Straw complained Wednesday to U.S. officials about their treatment of Islam, telling Secretary of State Colin Powell that “this action should not have been taken,” the Foreign Office confirmed.

The Foreign Office declined to say what he meant by “this action” – whether it was Islam’s detention, or his inclusion on the watch list.

Straw’s protest was a reversal of the Foreign Office’s hands-off position earlier Wednesday, when a spokeswoman had said “the reasons for his detention and return are obviously a matter for the U.S. and not for us.”

United Airlines Flight 919 had been en route to Dulles International Airport near Washington, D.C., on Tuesday when U.S. officials reviewing the passenger list discovered Islam was aboard. The aircraft was diverted to Maine’s Bangor International Airport, where federal agents met the plane and interviewed Islam.

“They diverted the plane at the last moment to a place called Bangor, which I’d never heard of, and suddenly I was surrounded by FBI who interrogated me,” Islam told reporters.

“I wasn’t handcuffed or anything like that,” he said. “They actually treated me very well. The one positive thing I can say is that a lot of security officers are pleased because they got my autograph.”

He was placed on a plane back to London on Wednesday. Islam’s 21-year-old daughter, Maymanah, was allowed to stay in the country.

“The whole thing was a terrible ordeal. I’m very tired. I was separated from my daughter. I really look forward to seeing her again,” Islam said.

Homeland Security spokesman Brian Doyle would say only that the intelligence community has recently obtained information that “further heightens concern” about Yusuf Islam.

“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.”

Asa Hutchinson, undersecretary for Homeland Security, told NBC’s “Today” show Thursday that “someone on the watch list should not be on the airplane flying. The responsibility falls on the airline under our current system.”

Islam said he had not been questioned by British police on his arrival. He said he was consulting lawyers and hoped to find out why he was barred.

“People make mistakes. I just hope they made a big mistake. We’ll see,” he said.