ISTANBUL — The Turkish authorities arrested a woman on Monday they suspect was behind the deadly bombing in central Istanbul a day earlier, saying she had been sent to Turkey from Syria by Kurdish militants to carry out the attack.
The bombing on Sunday on a crowded shopping street popular with both Turks and tourists killed six people — all of them Turkish nationals — who belonged to three different families, according to officials. It was the deadliest such attack in Turkey in more than five years, raising painful memories of the days when bombings by Kurdish and Islamic State militants often struck Turkish cities.
Turkey accused the United States of complicity in the attack because America has long maintained a military partnership with a Kurdish-led militia in Syria. Interior Minister Suleyman Soylu, during a visit to the site of the attack on Monday, dismissed condolence messages from the United States, saying this was like “the killer is among the first ones returning to the scene.”
The United States is an ally of Turkey in NATO, but Mr. Soylu’s accusation of complicity was rooted in the longstanding U.S. partnership with a Kurdish-led militia in northeastern Syria formed to battle the Islamic State, which ruled a so-called caliphate in parts of Syria and Iraq for years.
American officials have hailed the Syrian Democratic Forces, their Kurdish-led partners in Syria, as reliable and effective fighters who were essential to the U.S.-led effort to destroy the Islamic State, which was driven from its last patch of territory in Syria in March 2019.
But that partnership infuriated Turkey, which considers the Syrian militia a branch of the Kurdistan Workers’ Party, or P.K.K., a Kurdish group that has been fighting a war with the Turkish state for decades. Turkey, the United States and the European Union all consider the P.K.K. a terrorist group.
The U.S. Embassy in Turkey wrote on Twitter on Sunday that it was “deeply saddened” by the bombing.
“We extend our deepest condolences to the families of those who lost their lives and wish a speedy recovery for the injured,” it said.
A spokeswoman for the embassy did not immediately respond to a request for comment on Mr. Soylu’s accusation.
On Monday, the Istanbul police identified the suspect in the bombing as Ahlam al-Bashir and said that she had been arrested overnight in Istanbul.
The police said she had crossed into Turkey illegally from northern Syria to carry out the attack, adding that she had received orders from Kobani, a Kurdish city in northern Syria. The explosion had been caused by a small amount of TNT left in a bag on the street, the police said.
The authorities searched footage from 1,200 security cameras, raided 21 sites and detained 46 other people before finding her, the police statement said.
The P.K.K. denied any involvement in the bombing in a statement posted on the website of its armed wing. Mazloum Abdi, the commander of the Syrian Democratic Forces, also denied in a post on Twitter any connection to his forces.
During his visit to the bombing site, Mr. Soylu vowed that Turkey would retaliate, without specifics, and lamented the disruption of years of calm.
“We are embarrassed in front of our people on that matter,” he said.
For many Turks, the bombing recalled tense days from 2015-2017 when such attacks were more common.
The dead included a father and his 9-year-old daughter; a couple; and a mother and her 15-year-old daughter, officials said. More than 80 people were injured.
Istiklal Avenue, where the bombing took place, was open on Monday and visitors laid red flowers on a memorial at the site to commemorate the dead.