Two of the detainees were freed.US officials said on Friday the top suspect for the blast at the Israeli-owned Paradise Hotel in which 15 people including three attackers were killed was the Somali-based group Al-Itihad al-Islamiya, known also as AIAI or the Islamic Union.They said it was a prominent radical Islamist group in the Horn of Africa and had links with Osama bin Laden's al Qaeda, target