Turkish authorities have arrested a prime suspect and 16 others following a recent attack in Istanbul that left six people dead, according to state news agency Anadolu.
The public prosecutor's office accuses them of premeditated murder and "violating state unity," among other things, Anadolu said.
Several prosecutors had questioned 49 suspects allegedly linked to the attack.
Three suspects were subsequently released on conditional charges while 29 were expelled from the country.
Six people were killed and more than 80 injured in an explosion on Istanbul's busy Istiklal shopping street on Sunday.
Turkey blames the Syrian Kurdish militia YPG and the banned Kurdish Workers' Party PKK.
The PKK has denied the accusation.
According to Turkish police, the main suspect is a Syrian citizen.
Anadolu reported that the police investigation said the 23-year-old woman came into contact with the YPG through her partner in 2017.
Turkey classifies the YPG as an offshoot of the PKK and thus also a terrorist organisation.
In an interview with the public prosecutor's office, the woman stated that she had acted on the instructions of a man on the day of the attack, as Anadolu reported.
He is allegedly also a member of the YPG.
The man instructed her to wait on a bench and then leave a bag there.
After she did so, the explosion occurred and she ran away.
According to her statement, the woman did not know about a bomb in the bag she left behind, Anadolu reported.