AIDA Diva cruise ship

The cruise ship AIDA Diva reported seeing an explosion in the air over Ashdod, Israel, on July 7. The line since decided to avoid stopping at any Israeli ports this year. (Bernd Wuestneck / EPA)

First, U.S. airlines were banned from flying to Tel Aviv. Now some cruise lines said Wednesday that they will skip the Israeli port towns of Ashdod and Haifa because of the deadly conflict between Israelis and Hamas rebels.

Costa Pacifica canceled stops in Israel for departures from Sept. 15 through Nov. 20 and instead will visit Istanbul in Turkey and Volos, Greece, according to Travel Pulse. Costa Deliziosa also will substitute Istanbul as well as Volos and Heraklion, Greece, on a Sept. 5 cruise.

Regent’s Seven Seas Mariner and sister line Oceania replaced port calls in Israel on upcoming itineraries too.

Germany-based AIDA Cruises dropped Israeli ports from its itineraries after 2,700 passengers and crew members witnessed explosions in the air while in Ashdod on July 7. "The situation on board was calm," a  July 11 company statement says. "However, small particles that may have come from defense missiles according to first expert assessments were found on the open deck."

Holland America, which has upcoming cruises to both Israeli port towns on the Rotterdam and Prinsendam in fall, said it hasn't taken action yet.

"Holland America Line is closely monitoring the recent unrest in Israel and the Gaza Strip," a spokesman wrote via email. "The next ports calls in the area take place in October of 2014.  Should adjustments to upcoming itineraries be deemed necessary, the decision will be made closer to the call dates. The safety of our guests and crew is our top priority."

Meanwhile, the Federal Aviation Administration extended its ban on U.S.-Tel Aviv flights on Wednesday, stopping some but not all air traffic to the country.

The U.S. State Department warned Americans on Monday to consider deferring all nonessential travel to Israel and the West Bank.