01.15.19 Update: According to Reuters, German airport security staff have started a one-day strike. Lufthansa said it would cancel around 500 flights, 28 of which are intercontinental.

01.14.19 Update: Lufthansa announced it will cancel at least 414 flights due to a possible strike on Tuesday at eight German airports, including Frankfurt. The airline said the cancellations include 386 flights within Europe and 28 international flights.

Airline passengers planning on traveling to, from or through Germany’s Frankfurt Airport during this timeframe may have to find alternative plans.

According to a notification on Lufthansa’s homepage, due to a strike by security staff at the airport, a major European hub, Lufthansa Group flights to and from Frankfurt will be considerably hindered Tuesday, January 15.

The New York Times reported that Verdi, a German union, has “called on security staff at Frankfurt airport to go on strike on Tuesday to put pressure on firms in charge of screening passengers and luggage in wage talks.”

The Times also reports that Verdi said it is negotiating on behalf of 23,000 security workers in Germany and wage talks are to resume on Wednesday, January 23. According to multiple reports, if the strike does happen Tuesday, January 15 it will start at 2 a.m. local time and end at 8:00 p.m.

There were strikes at multiple airports across Germany the week of January 7, also related to the Verdi union negotiations. BBC News reported January 10 that German media said 350 out of 570 planned flights were cancelled in Dusseldorf; 130 out of 200 flights were cancelled in in Cologne; and 142 out of 270 in Stuttgart.

About 50 flights were canceled on Monday, January 7 at Berlin's Tegel and Schonefeld airports when security staff went on strike there.

Lufthansa stated that passengers with a Lufthansa flight departing from Frankfurt can immediately change their flights free of charge to a date between January 11 and 20, 2019.

The airline will publish flight cancellations in the afternoon on Sunday, January 13, and after that online rebooking will be also possible. Lufthansa offers the following tool to check flight status. It also said passengers who have entered their contact data online will be informed about their flight status.

Major U.S. airlines, including American Airlines and United Airlines, have posted travel advisories, along with terms and rebooking instructions for those traveling to or from Frankfurt on January 15.