On a day of celebration, 51 lives were taken by a suicide bomber in Turkey.
The dead were dancing at a wedding when a suicide bomber aged between 12 and 14 years blew himself up.
The bomb wounded 69 people, Mr Erdogan added, 17 of them seriously.
Turkey’s President Recep Tayyip Erdogan in a written statement published by local media (in Turkish), argued that there was “no difference” between IS, the Kurdish militants of the PKK, and followers of US-based cleric Fethullah Gulen, whom he blames for the coup attempt last month.
“Our country and our nation have again only one message to those who attack us – you will not succeed!” he said.
Eyewitnesses at the wedding said the ceremony was as good as over when they hand a loud bang and saw blood and body parts everywhere.
“The celebrations were coming to an end and there was a big explosion among people dancing,” said Veli Can, 25. “There was blood and body parts everywhere.”
The United States condemned the attack, calling it “barbaric act”.
Ned Price, a spokesman for the US National Security Council, said: “We stand with the people of Turkey as they defend their democracy in the face of all forms or terrorism.”
Turkey is still facing challenges since the July 15 coup which Erdogan blames on U.S.-based preacher Fethullah Gulen.