NEW : The Quartet urges all governments to discourage additional flotillas . The captain of The Audacity of Hope has been arrested , Greek authorities say . Comment: His ship is one of 10 in a flotilla meant to challenge Israeli 's blockade of Gaza .
NEW : The Quartet urges all governments to discourage additional flotillas . The captain of The Audacity of Hope has been arrested , Greek authorities say . The U.S. citizen is accused of disobeying authorities and putting passengers at risk . His ship is one of 10 in a flotilla meant to challenge Israeli 's blockade of Gaza .