Turkish Airlines will rebook, reroute, extend or refund tickets for passengers in response to the attack that occurred at Istanbul Ataturk Airport Tuesday evening, the company has announced.

The announcement applies to all bookings departing from, arriving at, or connecting in Istanbul Ataturk Airport or Sabiha Gökçen Airport between 28 June 2016 to 5 July 2016 (ticketed on or before 28 June 2016), providing that tickets are revalidated by 31 July 2016.

All claims will be processed at no cost, according to a company statement.

Gunmen and suicide bombers killed 41 people, at least 13 of them foreigners, and injured more than 230, in an attack on Tuesday evening at Turkey’s largest airport.

Early signs point to the attack being carried out by the so-called Islamic state, according to PM Binali Yildirim.

Doubts are growing about Istanbul’s safety as a tourist destination in the face of a terrorism crisis gripping that has hammered the city’s position as the fourth most visited in 2015.

Visitor numbers declined 28 percent in April after nine months of decline, the longest streak of year-on-year declines in statistics that span a decade according to data compiled by Bloomberg.