Two of the suicide bombers who caused carnage in the Paris massacre are thought to have sneaked into France by posing as refugees from Syria. The disclosure, which came amid claims of French intelligence failures, inevitably raised new security concerns about Europe’s borders. Police said the two men, who arrived in Greece last month, were among seven attackers, one as young as 15. One of the attackers was last night named by French media as Mostefai Ismaël Omar, 29, from Courcouronnes, in Essonne. Serbian media last night reported that one of the terrorists was named as Ahmed Almuhamed. The newspaper,...