• Several airlines suspended service to Israel after surprise attacks by Hamas and Israeli retaliation.
• United Airlines, Delta Air Lines and American Airlines each scrubbed service to Tel Aviv.
• Israeli airline El Al, Emirates and Turkish Airlines continued to operate.

Several airlines have suspended service to Israel after surprise attacks by Hamas and Israeli retaliation left hundreds dead and thousands injured.

State Department spokesman Matthew Miller said Monday that nine U.S. citizens were killed. Some U.S. citizens are still unaccounted for "and we are working with our Israeli partners to determine their whereabouts," he said.

A National Security Council spokesperson said that the U.S. is not "actively" considering an evacuation of U.S. citizens.

Meanwhile the U.S. Federal Aviation Administration on Saturday sent a notice to pilots stating "operators are advised to exercise extreme caution when operating" in the Tel Aviv area because of the attacks.

United Airlines, Delta Air Lines and American Airlines each scrubbed service to Tel Aviv.

Delta said Monday that it would suspend its nonstop flights to and from Tel Aviv through at least the end of October and said it will work with customers to get them out of Israel through partner airlines.

United Flight 954, which departed San Francisco Friday night for Israel, turned back near Greenland, according to flight-tracker FlightAware.

"Our Tel Aviv flights will remain suspended until conditions allow them to resume," United said on Sunday.

American flights scheduled for early this week were also canceled.

Germany-based Lufthansa Group said all of its flights, including those on Swiss International Air Lines and Austrian Airlines, were suspended into Tel Aviv.

Swiss International Air Lines is planning to send an Airbus A321 with seating for 219 passengers to Tel Aviv on Tuesday in coordination with the Swiss government "intended to offer Swiss nationals in Israel the opportunity of a prompt return to their home country."

All scheduled commercial service on the airline is canceled through at least Saturday.

"We regret having to do so," the airline said in a statement. "We are monitoring developments closely and remain in close contact with the relevant authorities."

British Airways also canceled flights this weekend and reduced service early in the week. Air France said its Tel Aviv service was canceled "until further notice," while European budget airlines Wizz and easyJet canceled flights to Tel Aviv through at least Monday.

Israeli airline El Al said Sunday that its flights were "operated as scheduled" and said it was expanding its schedule to help offset the cancellations. Emirates Airline also continued to operate flights between Tel Aviv to Dubai, and Turkish Airlines flew between Tel Aviv and Istanbul.

El Al and other carriers also offered travel waivers for customers to delay or cancel their trips.

Cruise operator Royal Caribbean said it adjusted several itineraries to bypass the area because of the attacks. "Impacted guests are being notified directly," the company said in a statement.

Some tour operators worked to get travelers out of the country quickly.

Nadav Peretz, founder of OUTstanding Travel, a Tel Aviv-based tour company that caters to the LGBTQ+ community, said he had more than 30 clients in the country at the time of the attacks and that customers quickly found flights out of the country and were refunded for the rest of their trips.

"Unfortunately, we had to send people back to the airport after two or three days of their trip," Peretz said by phone.

Intrepid Travel said it "had a small number" of travelers in the country when the attacks began on Saturday and that all guides and customers are accounted for.

Zina Bencheikh, managing director of Intrepid Travel's Middle East and Africa business, said that the company's customers who were in the middle of a tour in Israel during the attacks had mostly left the country, with the exception of one who was set to leave on Monday.

The company canceled its tours in Israel through the end of the month.