Cara Richardson

USA TODAY

An Islamic State suicide bomber possibly as young as 12 attacked a Kurdish wedding party in southeastern Turkey, President Recep Tayyip Erdogan said Sunday. At least 51 people died and 69 were hurt, he said.

The bombing late Saturday in Gaziantep, near Turkey’s border with Syria, was the deadliest attack in Turkey this year.

Erdogan, speaking on national television in front of Istanbul’s city hall, said the attacker was between 12 and 14 years old, the Associated Press reported.

Prime Minister Binali Yildirim condemned the bombing, which he said turned "a wedding party into a place of mourning" and he vowed to prevail over the "devilish" attacks, the AP said.

Gaziantep is about 75 miles from Aleppo, the Syrian city devastated by five years of civil war and recent Russian and Syrian airstrikes. The war has risked destabilizing Turkey, a NATO ally that has faced a wave of terror attacks this year and an attempted military coup in July.

Explosion at Turkish wedding ceremony kills at least 50

The U.S. State Department issued a statement condemning the "heinous attack" and extended condolences to the wounded and the loved ones of the victims.

"We stand by our ally and partner Turkey and reaffirm our commitment to defeating the common threat of terrorism," the statement said.

Erdogan, in his address, said it was clear the Islamic State had an organization in Gaziantep "or was attempting to make room for itself," the AP reported. "Many intensive operations were conducted, are being conducted. Of course our security forces will be conducting these operations with even greater intensity."

Turkey also blamed Islamic State terrorists, also known as ISIL or ISIS, for a June attack that killed 45 people in the June attack at Istanbul's Ataturk Airport. There were at least five terror attacks in Turkey in the first half of this year.

Turkish authorities imposed a temporary blackout on coverage of the bombing inside the country, the AP said.

Saturday's attack comes as the country is still reeling from last month's failed coup, which the government blamed on U.S.-based Muslim cleric Fethullah Gulen, who denies any involvement.

Several countries condemned the attack, including the United States, Sweden, Greece, France, Bahrain, Qatar and Jordan.