An attempted attack by a heavily armed man on a train in France last week was premeditated and well prepared, according to a French prosecutor. Security was stepped up on major European rail services as fears of “blowback” attacks by jihadis returning from Syria escalated after a gunman known to the intelligence agencies opened fire on a high-speed train bound for Paris. The name of the gunman was confirmed by French police as Ayoub el-Khazani,