Dogan said the two suspects held late yesterday were Kyrgyz nationals, identifying them only by their initials, K.V and F.M.I, aged 25 and 35 respectively.
Police found night-vision binoculars and military-style clothes in their suitcases, the agency said, along with two passports in different names.
They were questioned by anti-terror police in Istanbul. It was not clear whether they had been leaving or arriving at the airport.
Their detention came as 13 suspects, including three foreigners, were charged yesterday over the June 28 gun and suicide bomb assault at the airport that killed 45 people including 19 foreigners.
In total police have detained 29 people "including foreigners" in connection with the airport carnage, Prime Minister Binali Yildirim said yesterday.
Of more than 200 people injured, 49 are still in hospital including 17 in intensive care.
Authorities believe the attackers were a Russian, an Uzbek and a Kyrgyz national.
State news agency Anadolu has named two of them as Rakim Bulgarov and Vadim Osmanov, without giving their nationalities.
Central Asia's former Soviet republics have been a major source of foreign jihadists travelling to fight with IS and other extremist groups in Iraq and Syria.
