According to Turkish officials, at least six people were killed and 81 were injured in an explosion in a busy location in central Istanbul.
The interior ministry announced the arrest of a suspect.
The explosion occurred on Sunday at about 16:20 local time (13:20 GMT) at Istiklal Street near Taksim Square.
Istiklal Street is a lengthy pedestrian route that runs from Taksim Square to the Beyoglu neighborhood. It is surrounded by hundreds of shops and would have been bustling with pedestrians at the time of the explosion.
The perpetrators will be punished, according to President Recep Tayyip Erdogan. Vice President Fuat Oktay previously stated that the explosion was likely the result of a terrorist attack carried out by a woman.
He denounced the "vile attack" and claimed that "the smell of terror" was present during a news conference in Istanbul.
Bekir Bozdag, the justice minister, told Turkish media that a woman had been sitting on a bench nearby for more than 40 minutes before departing soon before the explosion.
According to Suleyman Soylu, the interior minister of Turkey, Kurdish separatists from the Democratic Union Party (PYD) and the Kurdistan Worker's Party (PKK) are most likely responsible for the deadly alleged bomb attack.
"It is PKK/PYD terrorist organization according to our preliminary findings," Soylu said in a press conference at the scene of Sunday's attack on Istiklal Avenue, Istanbul.
Soylu did not elaborate or provide details on how investigators arrived at this determination.
In a tweet, government minister Derya Yanik stated that a government ministry employee and his young daughter were among the victims. Yusuf Meydan, an employee of Turkey's Ministry of Family and Social Services, and his daughter Ecrin were among those slain, according to Yanik.
Condolences for Turkey have poured in from all over the world in the aftermath of the incident.
According to White House press secretary Karine Jean-Pierre, the U.S. stood "shoulder-to-shoulder" with its NATO ally in "countering terrorism."
According to Soylu's report from Monday, 31 of the 81 injured patients have yet to be treated while 50 have been released from the hospital.
Tens of thousands of people have died during the course of Turkey's four-decade battle with Kurdish separatist parties. Turkey, the U.S., and the European Union have all recognized the PKK as a terrorist organization.
One of the city's main thoroughfares, Istiklal Street, which is frequently crowded with shoppers, was previously the target of a suicide bomber in 2016.
