Delta will suspend all flights from New York City to Tel Aviv for the remainder of August, the airline announced Monday, amid growing fears of a regional conflict between Israel and Iran.

The announcement extends a previous suspension that began last week. Sales of all flights between New York’s John F. Kennedy International Airport and Tel Aviv this month have halted, the airline said.

Any customers with tickets on affected flights will be issued a travel waiver. Flights on partner airlines Air France and EL AL Israel Airlines are still available, Delta said.

“Delta is continuously monitoring the evolving security environment and assessing our operations based on security guidance and intelligence reports and will communicate any updates as needed,” the company said in a statement.

United Airlines similarly paused flights to Tel Aviv “until further notice” last week, citing “security reasons.”

The cancellations come after Israel killed two top Hamas leaders in strikes on Tehran and Beirut, ratcheting up concerns that Israel could escalate to all-out war in Lebanon, where Hezbollah militants are located. The Iranian government has also promised retaliation for the strikes, leading the U.S. military to deploy significant assets in the region.