Pilots at German airline Lufthansa have extended their two-day strike to long-haul flights in an ongoing dispute over retirement benefits.

The airline, Germany's biggest, says a total of 1,350 of its 2,800 flights scheduled through the strike's end Tuesday at midnight have been cancelled, affecting 150,000 passengers.

On Monday, the strike was primarily focused on inner-Europe flights. Lufthansa said some of its cargo flights were rescheduled, but none had to be canceled.

Lufthansa says the other airlines in its group — Germanwings, Swiss, Austrian Airlines, Brussels Airlines and Air Dolomiti — are not affected.

The strike follows failed talks with the Vereinigung Cockpit union, which is demanding Lufthansa keep paying a transition payment for those wanting to retire early. The airline wants to cut those payments, citing increasingly tough competition.