Three suicide bombers armed with guns as well as explosives hit Istanbul's Ataturk International Airport late Tuesday, killing 36 and wounding dozens more.
"There was a huge explosion, extremely loud. The roof came down. Inside the airport it is terrible, you can't recognize it, the damage is big," said Ali Tekin, who was at the arrivals hall waiting for a guest when the attack took place.
A German woman named Duygu, who was at passport control entering Turkey, said she threw herself onto the floor with the sound of the explosion. Several witnesses also reported hearing gunfire shortly before the attacks.
"Everyone started running away. Everywhere was covered with blood and body parts. I saw bullet holes on the doors," she said outside the airport.
There was no immediate claim of responsibility for the latest in a string of suicide bombings in Turkey this year, but the Dogan news agency said initial indications suggested Islamic State may have been responsible, citing police sources.
A Turkish official said it was too soon to assign blame.
The attack bore some similarities to a suicide bombing by Islamic State militants at Brussels airport in March which killed 16 people. A coordinated attack also targeted a rush-hour metro train, killing a further 16 people in the Belgian capital.
Paul Roos, 77, described seeing one of the attackers "randomly shooting" on the departures floor of the terminal.
"He was just firing at anyone coming in front of him. He was wearing all black. His face was not masked. I was 50 meters (55 yards) away from him," said Roos, a South African on his way back to Cape Town with his wife after a holiday in southern Turkey.
Both Turkish nationals and foreign tourists were killed in the attack, but to see something like this happen during Ramadan is going to draw nearly immediate accusations of Islamic State from President Erdogan, regardless.