Turkish F-16s had launched the air raid on December 29 intending to target Kurdistan Workers' Party (PKK) militants after the drone spotted a group moving toward its sensitive southeastern border at night, according officials in Ankara.

"We're familiar with the incident," said the US defense official, who spoke on condition of anonymity.

"In this particular case, they (drone operators) did notice a group of people and some pack animals. That information was passed on to the Turks and then our drones departed the area."

The United States has Predator unmanned aircraft based in the country and regularly relays information on Kurdish forces gathered from surveillance flights to Turkey's military.

"We had nothing to do with the air strike, in fact we were not in the area when the strike occurred," the official added.

The Turkish army, however, denied that the intelligence that led to the killing of civilians was obtained from US drones, saying that the images were taken by Turkish military's unarmed aerial vehicles.

"The allegations that initial images of the incident ... were provided by US unarmed Predator drones do not reflect the truth," it said in a brief statement posted on its website Thursday.

The botched air strike triggered a wave of protests by Kurds who accused the government of carrying out a "massacre."

Clashes between Kurdish rebels and the army escalated late last year.

The PKK took up arms in Kurdish-majority southeastern Turkey in 1984, sparking a conflict that has claimed about 45,000 lives. It is labeled a terrorist organization by Ankara and much of the international community.