Hundreds of El Al passengers on four departing flights were stranded in Ben Gurion Airport Thursday, because the pilots never showed up for work, according to Maariv-NRG.

The pilots are not answering their cell phones and their whereabouts are unknown. El Al management said that the pilots appear to be carrying out a protest motivated by a work dispute.

El Al, Israel’s national carrier, published an announcement according to which “due to unavailability of air crew members, there have been disruptions today in El Al’s flight schedule. El Al has had to deal with disruptions in schedules and plane placement lately, due to pilot unavailability and their non-compliance with the company’s requests to carry out flights.”

The airline went on to say that its director, David Maimon, and the management, “are looking for ways to carry out the commercial plan of the company, which operates in a difficult competitive environment, and get the flights to take off as scheduled, with minimal harm to the passengers.”

The airline added that it apologizes to the clients who are suffering as a result of the delays and is taking action to get them to their destinations as fast as possible.