According to an official, Turkish police have apprehended a suspect in the bombing in central Istanbul that left at least eight people dead and 81 more wounded.

Monday, Turkish interior minister Suleyman Soylu informed reporters that the suspect in custody was "the individual who left the device that caused the explosion" on a famous boulevard in the country's largest metropolis.

Soylu attributed Sunday's explosion on Istiklal Avenue to the banned Kurdistan Workers' Party (PKK), stating: "Our judgment is that the command for the horrific terror act came from Ayn al-Arab [Kobane] in northern Syria," where he noted the group's Syrian headquarters are located.

"We will react against those guilty for this horrible terrorist attack," he added, adding that the death toll had grown from six to eight and that 81 people were injured, with two in "serious condition."

Nobody has yet claimed responsibility for the explosion.

Sunday, Turkish President Recep Tayyip Erdogan branded the explosion as "treacherous" and "reeking of terrorism." Before departing for the G20 summit in Indonesia, Erdogan stated that preliminary information revealed that a woman was involved in the attack.

Later on Sunday, Justice Minister Bekir Bozdag told A Haber television that the woman was spotted sitting on a bench on Istiklal Avenue for about forty minutes.

According to him, the explosion occurred a few minutes after she stood up.

Two alternatives exist, he told A Haber. This bag either has a device that causes it to explode, or it is remotely detonated.

Al Jazeera has images of the lady believed to be responsible for the bombing.

Monday's notice by Soylu had no additional information on the woman.

Kurdish separatists, ISIL (ISIS), and other groups have previously targeted Istanbul and other Turkish cities, including a series of attacks in 2015 and 2016.

In December 2016, twin bombs outside a football stadium in Istanbul killed 38 people and injured 155. An offshoot of the PKK, which has fought for Kurdish autonomy in southeastern Turkey since the 1980s and is classified as a terrorist organization by Turkey, the European Union, and the United States, claimed responsibility for the attack.

Regularly targeted by Turkish military operations, the PKK is also at the center of a dispute between Sweden and Turkey, which has blocked Stockholm's entrance into NATO since May because Sweden is too lenient with the PKK.

Several countries, including Azerbaijan, Egypt, France, Greece, Italy, Pakistan, Ukraine, the United Kingdom, and the United States, issued condemnations of Sunday's attack and condolences to the victims.

Greece "unequivocally" condemned the explosion and offered condolences, while the United States stated that it stands "shoulder to shoulder" with its NATO ally in the fight against terrorism.

In a statement to the Turkish people, French President Emmanuel Macron declared, "We feel your grief." In the fight against terrorism, we stand with you."

President of Ukraine Volodymyr Zelenskyy tweeted in Turkish, "The suffering of the loving Turkish people is our suffering."

President of the European Council Charles Michel also tweeted condolences: "My sympathies are with the victims and their families."