Turkish authorities on Tuesday detained two foreign nationals at Istanbul's main airport over suspected links to a nightclub attack claimed by Daesh that killed 39, Dogan news agency said. The pair were detained on entering Ataturk International Airport and have been taken to Istanbul police headquarters for questioning, it added. The government said Monday that eight people had been detained but the number then increased to 14 after new detentions in the Anatolian city of Konya. The main suspect, who remains at large, was staying in a rented flat in Konya before moving to Istanbul to carry out the attack, press reports said. He has not been named but is reportedly from Central Asia. The airport detentions bring the total number of arrests over the attack to 16. Anadolu Agency said Tuesday all detained suspects were being questioned at Istanbul's main police headquarters. Turkish tourism industry professionals marched to the nightclub where 39 people were killed, in a show of solidarity and to protest a spate of attacks that has crippled the sector.