Celebrity Cruises canceled a visit to Istanbul earlier this week due to concerns with terrorism. The cancellation involved the Celebrity Equinox, which had a scheduled overnight call at Istanbul on August 24, Monday.

Yesterday, August 26, the line canceled more port calls, announcing that the Celebrity Reflection will not stay in the port of Istanbul on August 31 and will saill off earlier in the day. Celebrity Cruises will also skip the port call of Celebrity Reflection at Istanbul on September 4 and 5 and will instead stop in Athens

On August 19, Costa Cruises canceled all calls in the port city for the remainder of 2015. Cruise lines are under pressure not to transport more passengers into danger like Costa did when it sailed to Tunis in March, which resulted in passengers being slaughtered. 

The skipped calls come as a reaction to concerns about passengers' safety following a deadly terrorist attack near the U.S. Consulate in Turkey's largest city earlier this month. 

The U.S. Department of State issued a “security message” saying that "due to a record of past terrorist attacks in Turkey and a continuing threat from both transnational and indigenous groups, the threat level for the possibility of further terrorist attacks against U.S. citizens and interests remains critical". The U.K. Foreign and Commonwealth Office also cautious citizens to travel carefully.