Pilots at German airline Lufthansa have launched a two-day strike in a pay dispute, a walkout that has forced the company to cancel nearly 900 flights on Wednesday alone.

The Cockpit union initially called members out on a 24-hour strike Wednesday. Late Tuesday night, after Lufthansa tried and failed to have courts block the walkout, it said that they would also strike on Thursday.

The company canceled 876 of the Lufthansa group's planned 3,000 flights on Wednesday and said that around 100,000 passengers were affected. It expressed "complete incomprehension" at Cockpit's decision to extend the strike.

Other Lufthansa group airlines such as Eurowings, Swiss and Austrian Airlines aren't affected by the walkout.

The latest strike by Cockpit is the 14th since April 2014 in the long-running dispute.