The suspect of the deadly blast in the Turkish largest city of Istanbul confessed to police that she carried out the bomb attack, Turkish authorities announced Monday.
The Istanbul Police Department said in a statement that the suspect was a Syrian national named Ahlam Albashir and she confessed that she received the attack order from the outlawed Kurdistan Workers' Party (PKK) and its offspring in Syria, the People's Protection Units (YPG).
The PKK/YPG are both listed as terror organizations by Ankara.
Albashir said she was trained as a special intelligence officer by the terror organizations and entered Türkiye illegally through Afrin, Syria, with the attack plan, according to the police.
On Sunday, an explosion hit the busy Istiklal Avenue on the European side of Istanbul at 4:20 p.m. local time (1320 GMT), leaving six dead and 81 wounded.
The explosive used in the attack was trinitrotoluene TNT, one of the high-powered explosives, the police said in a separate statement.
The state-run Anadolu agency said 46 suspects, including the assaulter, have been detained in police operations carried out at 21 addresses in Istanbul.
Meanwhile, Turkish Interior Minister Suleyman Soylu on Monday visited the scene twice and left carnations in memory of those who lost their lives.
"We do not accept the condolences of the American embassy (about the deadly blast)," Soylu told reporters.
Following the blast, the U.S. embassy in Türkiye "strongly condemned the act of violence" in Istanbul, conveying condolences for those who lost loved ones in the attack, it said on Twitter.
Ankara has long been blaming Washington for aiding and supporting the PKK and YPG.