Istanbul Ataturk Airport was hit by a major terrorist attack June 28. The airport, which carries more than a million passengers a week and ranks as Europe’s third largest, was attacked by three terrorists around 10 p.m. when they arrived in a taxi whose driver was probably unaware of the motives of his customers. The attackers apparently had AK-47 rifles, which they fired randomly, and suicide bomb vests, which they activated both in outside and inside the arrival level of the international terminal.

At least 41 people lost their lives, and more than 239 were injured. Most victims were Turks; others were foreigners from Iraq, China, Saudi Arabia, Iran, Tunisia, Jordan, Uzbekistan, Switzerland and Ukraine. The overwhelming majority of the victims were Muslims who were ruthlessly killed in the middle of the Muslim holy month of Ramadan.

Who carried out this attack? During the initial hours it was not clear. The usual suspects included both the Islamic State (IS) and the Kurdistan Workers Party (PKK), the militant pro-Kurdish group that has been at war with the Turkish government for decades. My first guess was IS, because the PKK’s attacks often target the police or military without minding the “collateral damage.” But this attack was a totally random slaughter of innocents like in Paris and Brussels. No wonder Turkish Prime Minister Binali Yildirim pointed to IS as “the prime suspect.”

We will probably learn more about the identity of the three terrorists in the coming days or weeks. So far, Turkish authorities have only announced that their bodies are torn apart and they are suspected to be foreigners, not Turkish citizens.