The attack was the deadliest in a series of bombings in Turkey this year, and President Tayyip Erdogan said Islamic State was likely behind it.
“Initial evidence suggests it was a Daesh attack,” Erdogan said in Istanbul on Sunday, using an Arabic name for the hardline Sunni Islamist group. He said 69 people were in hospital and 17 were “heavily injured”.
A destroyed suicide vest was found at the blast site, officials said.
Islamic State has been blamed for other similar attacks in Turkey, often targeting Kurdish gatherings in an effort to inflame ethnic tensions. The deadliest was last October, when suicide bombers killed more than 100 people at a rally of pro-Kurdish and labor activists in Ankara.
Saturday’s attack comes with Turkey still in shock just a month after Erdogan and the government survived an attempted coup by rogue military officers, which Ankara blames on U.S.-based Islamist preacher Fethullah Gulen. Gulen has denied the charge.
The pro-Kurdish Peoples’ Democratic Party (HDP) said the wedding party was for one of its members. The groom was among those injured, but the bride was not hurt.
The bomb went off as guests spilled out into the streets of the city close to the Syrian border after the traditional henna night party, when guests have their hands and feet painted.
Women and children, including a three-month-old baby, were among the dead, witnesses said.
Blood and burn marks stained the walls of the narrow lane where the blast hit. Women in white and checkered scarves wept outside the morgue waiting for word on missing relatives.
“The celebrations were coming to an end and there was a big explosion among people dancing,” said 25-year-old Veli Can. “There was blood and body parts everywhere.”