Tourist From Mass. Escapes Attack At Istanbul Airport

BOSTON (CBS) - At least 36 people are dead and dozens more are injured following a terrorist attack at Turkey's busiest airport. The investigation is underway to determine who's responsible, but a U.S. intelligence source says the violence has all the hallmarks of an ISIS attack.

A Massachusetts tourist is also recounting his harrowing experience.

"They had cuts and people were very badly injured," said Adam Keally. "One guy had holes in his back from shrapnel or from glass. That's what I was holding."

Adam Keally is from the Boston area and was inside Istanbul's Ataturk airport during the attacks.

Video captures what appears to be the moment a suicide bomber detonated an explosive device inside the airport.

Related: Turkish Travelers Land In Boston, Learn Of Attacks

The city's governor reported as least three people blew themselves up in a terror attack at the international terminal. One Turkish official said the suspects opened fire before they detonated explosives.

A U.S. intelligence official confirms the attackers had grenades, automatic weapons and suicide vests.

People inside, including Keally, ran from the building following the blasts.

"People were shooting from one side and we all ran the other way and then the bombs went off and people started running the other way and there was more shooting and we came out," Keally said.

The violence came during the holy month of Ramadan. Turkey's president said it "shows that terrorism strikes with no regard to faith and values."

Islamic state and Kurdish militants have recently taken responsibility for several attacks in Turkey, some aimed at tourists.

The State Department issued a renewed warning Monday indicating that there were terrorist threats to be concerned about in Turkey.