Cruise companies are being forced to cancel or reroute voyages as tensions in the Red Sea escalate.

Royal Caribbean, Carnival Corporation and MSC Cruises are among those who’ve made the decision to adjust their itineraries, or pull voyages completely, to avoid passing through the Red Sea due to attacks by the Iran-backed Houthi militia in Yemen.

Carnival Corporation has become the latest to announce changes to itineraries, confirming that it will reroute 12 ships across seven of its brands in May in order to avoid passing through the Red Sea.

In a statement released on Tuesday, the cruise operator stressed that it was “committed to the safety and well-being of its guests and crew” and had been “actively monitoring the situation in the Red Sea and surrounding region.”

It did not indicate which sailings were likely to be affected.

However, a number of Carnival Corporation brands, including Costa Cruises and Seabourn, have already announced cancellations and amendments to itineraries.

Costa Cruises recently announced that it was canceling a repositioning voyage scheduled to sail through the Red Sea in March.

“Given recent developments on the security environment and future uncertainties in the area, working in close consultation with global security experts and government authorities, we have made the difficult decision to cancel the cruise that was originally planned,” Costa said in a statement sent to those due to travel on the 19-night cruise from United Arab Emirates to Italy.

Meanwhile, a passenger on board a round-the-world cruise on Princess Cruises’ Island Princess tells CNN that customers have been informed that the voyage will no longer be stopping at a number of destinations across Asia, the Middle East, Australia and New Zealand. CNN has contacted Princess Cruises, another Carnival Corporation brand, for comment.

Earlier this month, MSC Cruises canceled at least three repositioning voyages due to depart in April, including a 24-night cruise on board MSC Splendida from Durban, South Africa to Genoa, Italy as a result of the situation in the Red Sea.

Silversea also confirmed that it had canceled two upcoming voyages on board Silver Moon and “amended” the itinerary of a sailing between Aqaba, Jordan and Muscat, Oman to allow guests to disembark in Piraeus, Athens.

“We took care of arranging guests’ onward journeys from the new port of disembarkation,” a spokesperson for Silversea confirmed to CNN.

The adjustments come after a series of attacks by Houthi rebels on vessels transiting through the Red Sea and the Suez Canal, which resulted in US and UK military strikes against Houthi targets earlier this month.