Homegrown attacks rising worry in U.S. as Islamic State weakens abroad

FILE PHOTO: A New York City Police (NYPD) officer stands in the subway corridor, at the New York Port Authority subway station near the site of an attempted detonation the day before, in New York City, U.S. December 12, 2017. REUTERS/Brendan McDermid/File Photo

NEW YORK (Reuters) - The online video's message was clear: Supporters of Islamic State who could not travel overseas to join the militant group should carry out attacks wherever they were in the United States or Europe.

Bangladeshi immigrant Akayed Ullah, 27, followed those instructions on Monday when he tried to set off a homemade bomb in one of New York's busiest commuter hubs, in an attack that illustrates the difficulty of stopping "do-it-yourself" attacks by radicals who act alone.