Lufthansa cancelled half of all its long-haul flights for the second time this week after pilots went on strike on Thursday over a retirement benefits dispute. The latest strike began at 3 a.m. local time (9 p.m. Wednesday EST) and is the tenth strike since April this year. 

The strike has mostly affected flights from Frankfurt, Dusseldorf and Munich, Deutsche Welle, a local news agency reported. The pilots are opposing the airline's move to do away with an early retirement plan that allows pilots to retire at the age of 55, and receive 60 percent of their regular salary until the standard retirement age of 65.

Earlier this week, Lufthansa cancelled 1,350 flights after pilots staged a strike, affecting more than 150,000 passengers. Two days later, the company offered mediation with the German pilots’ union Vereinigung Cockpit (VC), which represents nearly 5,400 pilots.

“Despite the labour action Lufthansa is able to offer about half of the scheduled long-haul flights to its passengers,” Lufthansa announced Wednesday, in a statement, adding: “All Lufthansa short and medium – haul flights as well as flights operated by the Lufthansa Group airlines Austrian Airlines, Brussels Airlines, Germanwings, SWISS and Air Dolomiti (operated by OS, SN, 4U, LX, EN) will not be affected.”

Almost 50 percent of the flights will be grounded and Lufthansa Cargo will operate only nine of the 15 flights, BBC reported.

Lufthansa would "have to live with" the ensuing strikes due to the board's decisions, CEO Carsten Spohr told BBC. "We hope that we won't have any more strikes for the sake of our passengers, shareholders and employees," he said. The pilot union, in a statement announcing the latest strike, said it expected a clear commitment from the airline's management.

The strike is expected to end at midnight local time (6 p.m. EST). The list of flights that have been cancelled can be found here.