U.S. airlines said Wednesday that they have paused flights to Tel Aviv after deadly conflict in Israel intensified in the worst outbreak of violence there since 2014.

American Airlines said it canceled its service between New York’s John F. Kennedy International Airport and Tel Aviv scheduled for Wednesday and Thursday, while United Airlines called off service to Tel Aviv from Chicago and from Newark, New Jersey on Tuesday and from San Francisco and Newark to Tel Aviv on Wednesday. Delta Air Lines said it canceled JFK-Tel Aviv service on Wednesday.

Airlines have an average of seven flights a day scheduled to Tel Aviv from the U.S. this month, according to aviation data firm Cirium.

Israeli airline El Al said Wednesday that it planned to continue operating flights as scheduled but said that passengers can change their flights without paying a fee or cancel in exchange for a voucher.

Israeli authorities had briefly halted flights at Tel Aviv’s Ben Gurion Airport earlier this week after Hamas fired rockets toward Tel Aviv, Reuters reported.

“Additionally, In order to allow our customers to keep in touch with their families during the flight, EL AL will allow free use of the WhatsApp service on flights that have WiFi,” the carrier said.