Greek Orthodox Archbishop Boulos Yaziji and Syriac Orthodox Archbishop Yohanna Ibrahim were abducted from their car in Aleppo in April after returning from a humanitarian mission in Turkey.
Their driver, a deacon, was shot and killed immediately.
Although the final fate of the two archbishops is unknown, it is thought that they were killed soon after their kidnap.
According to Hürriyet Daily News, the suspects were captured by police conducting a security check on a road between Konya, in central Turkey, and the capital Ankara.