A London-to-Washington flight was diverted to Maine after it was discovered that passenger Yusuf Islam, formerly known as the singer Cat Stevens, was on a government watch list and barred from entering the country. Islam "was interviewed and denied admission to the United States on national security grounds," a spokesman of the US department for Homeland Security told the news agency AP. He was questioned by immigration and FBI officials and will be deported on Wednesday. Officials had no details about why Stevens/Islam might be considered a risk to the US. The singer turned "peace activist" had visited New York in May for a charity event and to promote a DVD of his 1976 tour. Last year he released two songs, including a re-recording of his 1970s hit "Peace Train," to express his opposition to the US-led war in Iraq.