A suicide bomber as young as 12 killed at least 51 people at a wedding party in Turkery.
The bomber attacked guests dancing on the street in the Turkish city of Gaziantep near the Syrian border.
Saturday'a attack was the deadliest in a series of bombings in Turkey this year, and President Tayyip Erdogan said yesterday that Islamic State (IS) was likely behind it.
Turkey faces multiple security threats from militants at home and from Syria.
"Initial evidence suggests it was a Daesh attack," Erdogan said, using an Arabic name for the hardline Sunni group during a visit to Gaziantep after the attack. He said 69 people were in hospital and 17 were "heavily injured".
Islamic State has been blamed for other 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 labour activists in Ankara.
The latest attack comes with Turkey still in shock only a month after Erdogan and the government survived an att- empted coup by rogue military officers, which Ankara blames on US-based Islamist preacher Fethullah Gulen. Gulen has denied the charge.
Saturday's wedding party was for a member of the pro-Kurdish People's Democratic Party, it said, and the groom was among those injured. The bride was not hurt.
Celebrations were ending at the traditional henna night party, when guests have decorative paint applied to their hands and feet.
Some families had already left when the bomb went off, but women and children were among the dead.
Blood and burns marked the walls of the narrow lane where the blast hit. Women in white and checkered scarves wept as they sat cross-legged 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."
Another witness, Ibrahim Ozdemir, said: "We want to end these massacres. We are in pain, especially the women and children."
NATO member Turkey is a partner in the western coalition against IS in Iraq and Syria, allowing US jets to fly attacks against the group from its air bases. It has also backed some rebel groups in Syria.
Syrian rebels were preparing to launch an operation to capture a town held by IS at the border with Turkey, a senior Syrian rebel said.
Hundreds gathered yesterday for funerals, some weeping over coffins draped in the green of Islam, local TV images showed. Other funerals would have to wait because many of the victims were blown to pieces and DNA forensics tests would be needed to identify them, security sources said.
In Gaziantep, the chief prosecutor's office said they had found a destroyed suicide vest at the blast site. Three suspected Islamic State suicide bombers killed 44 people at Istanbul's main airport in June.
Violence flared again last week in the largely Kurdish southeast. Ten people were killed in bomb attacks, mostly police and soldiers, in an escalation that officials blamed on the militant Kurdistan Workers' Party (PKK).
Turkey began air strikes against IS last August, in the weeks after a peace process with the PKK collapsed, and it also began targeting PKK targets in northern Iraq.
Half-an-hour from Gaziantep is the border town of Kilis, which has been repeatedly hit by rockets and shelling from IS territory.
Yesterday, ruling AK Party lawmakers as well as Erdogan emphasised that they see IS as no different from the PKK and the group led by Gulen, all three classified by Turkey as terrorist organisations.