The Levant News -- Police in Turkey raided 16 addresses in Istanbul early this morning and detained 13 people, including three foreigners, in response to Tuesday’s bombing of the Ataturk international airport. The death toll from the attack now stands at 42, with 128 people in hospitals, including 41 in intensive care units. Officials are still withholding public comment on the identity of the attackers and their organization, although Prime Minister Binali Yildirim has pointed the finger at the Islamic State. One unnamed government official told Reuters that the attackers were from Russia, Uzbekistan and Kyrgyzstan. Yildirim said physical and x-ray checks at airports have proven inadequate. He called for additional security measures, particularly more specially trained personnel at airport entrances. Meanwhile, reports emerged that Turkish intelligence units had warned three weeks ago about a potential IS attack targeting the airport and other landmarks. “Intelligence units sent a warning letter to the top of the state and all its institutions in early June, around 20 days ago, about Istanbul,” CNN Turk TV’s Hande Fırat said in a live broadcast. Reports said based on that warning security at the airport was reinforced and more experienced security personnel were deployed.