Turkish police said they detained 13 people in connection with the terror attack at Istanbul’s Ataturk airport that killed 42 people, local media reported.

Turkish police said they detained 13 people in connection with the terror attack at Istanbul’s Ataturk airport that killed 42 people, local media reported.

Three foreign nationals are among the suspects arrested in Istanbul on Thursday, the semi-official Anadolu news agency reported.

Authorities believe the ISIL is behind the attack, which wounded more than 230 people. An official claim of responsibility has not been forthcoming.

Earlier Thursday, nine suspects linked to the ISIL group, were arrested in large-scale police raids in the coastal city of Izmir, Anadolu reported.

Police said they found three hunting rifles and documents relating to the extremist group during the searches, according to the agency.

Turkish authorities declared a day of national mourning after the attack, which was carried out by three suicide bombers late Tuesday.