Turkey has declared a national day of mourning after the attack, the most deadly this year.

This is the seventh major terrorist attack in Turkey since January, and the fourth attack in Istanbul, where populated areas including Sultanahmet, Istiklal, and Vezneciler, have been targeted. It comes just at the end of the holy month of Ramadan, and a heightened sense of anxiety has spilled over into daily life.

“This is an atmosphere of instability, not knowing what may happen anywhere,” Nihan Kaya, a writer and psychologist in Istanbul, told Quartz.

While Turkey is a relatively new target, extremist terrorist groups like ISIL and Al Qaeda have overwhelmingly targeted Muslim-majority countries in recent years.

Up-to-the minute data of global terror victims doesn’t exist, but the countries that saw the most deaths from terrorism in 2014, the last year that full data was available, are overwhelmingly Muslim (Nigeria, which is about 50% Muslim, was under siege by Boko Haram):

While no one has taken responsibility for Tuesday’s attack, ISIL is the chief suspect, Turkish officials say. Officials called for support from the rest of the world, and especially Western countries, to help defeat terror organizations.

“The attack, which took place during the holy month of Ramadan, shows that terrorism strikes with no regard for faith and values,” Turkish president Recep Tayyip Erdogan said. “Nor do terrorists distinguish between their victims.”

The president of the Ministry of Religious Affairs (Diyanet), Dr. Mehmet Görmez, condemned the “filthy” attacks, that were “carried out with a total lack of decency, shame, and morality.”

Ordinary people in Istanbul, meanwhile, struggled to come to terms with the attacks.

“I’m feeling so sad to witness that incident take place in my hometown. I still cannot understand how there is a security gap in one of the biggest and crowded airports,” says Kıvanç Başkaya, a student.

Others have moved out of Istanbul entirely in recent months. “I changed my life totally. I was living in Istanbul. Now, I live in a small touristic village in Marmaris on Aegean coast of Turkey,” said Ozan Önen, a columnist. “I don’t use crowded airports anymore.”

Hours after the attack, US presidential candidate Donald Trump responded by tweeting “We must do everything possible to keep this horrible terrorism outside the United States,” echoing his earlier calls to ban Muslims from the country.

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