Turkish anti-terror police detained 159 suspects, including 133 foreigners, in operations against the Daesh terrorist group in Istanbul on Friday.

Twenty-six suspects are being interrogated while the rest are set to be deported. The police did not reveal the identities or nationalities of the foreigners.

Security sources said a large amount of documents containing Daesh propaganda were found in the possession of the suspects. The police also found a pistol hidden in a carved-out page of a book during the search of the suspects' residences.

The suspects are accused of promoting terrorist propaganda and recruiting militants for Daesh as well as "providing logistics support" to the group active in Syria and Iraq. As many as 1,338 suspects, including 694 foreigners, were arrested in Turkey last year for having links to the Daesh terrorist group. Additionally, a total of 339 major terror plots were prevented as a result of the seizure of 247 explosives and 61 bomb vehicles in 2016.Following the New Year's attack at a popular Istanbul nightclub, where 39 people were killed by a Daesh gunman, Turkey launched nationwide operations that have netted hundreds of suspects.