The move comes after 10 people were killed in a bomb blast in Istanbul, at least nine of which were believed to be German tourists.

Crystal said on Friday that it would be re-routing two of its upcoming voyages on Crystal Symphony’s April 24 and May 1, which had been set to call at Istanbul and Kusadasi, replacing these ports with Greek destinations.

“The safety and peace of mind of our guests are our primary concerns and we do not take any risks with either,” says Crystal chief executive and president, Edie Rodriguez.

“The itinerary changes will allow our guests to continue with their planned holidays in the same standard of excellence and luxury, without the added worry of security in a particular destination.”

Turkish ports of call scheduled for April and November onboard Crystal’s new luxury yacht, Crystal Esprit, will also be changed for calls in Greek ports, the line said.

For both sailings, pre-reserved Crystal Adventures will automatically be cancelled, while the line said it was is in the process of developing new shore excursions.