Turkey faces multiple security threats, including the militant Kurdistan Workers Party (PKK) in the largely Kurdish southeast and Daesh (ISIL) terrorists. Both groups have been blamed for multiple deadly bomb attacks in Turkish cities over the last year.
The interior ministry said in a statement that 1,589 people were detained for questioning over suspected militant links. While 125 of them were arrested, it was not immediately clear how many remained in detention.
A total of 1,067 of those detained were suspected of links to the autonomy-seeking PKK, which has carried out a three-decade insurgency against the Turkish state and is considered a terrorist organization by the United States, Turkey and the European Union.
Another 501 were detained for suspected ties to the US-based cleric Fethullah Gulen, whom Ankara blames for orchestrating an attempted coup in July. Gulen denies any involvement and has condemned the coup.
Twenty-one people were detained for alleged ties to Daesh, the ministry said, Reuters reported.
Of those arrested, 57 were charged with links to the PKK, 63 to the cleric Gulen and five to Daesh, the ministry said.
Following the July 15 coup, Turkey has arrested more than 40,000 people and sacked or suspended more than 100,000 in the military, civil service and private sector. Rights groups and some Western allies fear that the crackdown is leading to a curtailment of civil liberties.
The government says such measures are necessary, given the security threat.