Hundreds of Lufthansa flights were cancelled on Thursday as pilots and flight attendants went on strike at Germany’s largest airline, which has for years struggled to rein in costs at its core brand.The company did not initially provide a number of affected connections and passengers, but said that the strike action is leading to “extensive cancellations”.German airport association ADV estimated that more than 460 flights will be cancelled, with almost 70,000 passengers affected.Departure boards for Frankfurt and Munich, Lufthansa’s hubs in Germany, showed most flights were cancelled for the day, including to overseas destinations.Lufthansa earlier said it would try to rebook passengers on its other airlines or partner airlines before returning to its normal schedule on Friday.The walkout, organised by pilots’ union VC and flight attendants’ union UFO, comes as the Berlinale film festival starts in the German capital on Thursday, and politicians and military officials gather for the Munich Security Conference, which will commence on Friday.Pilots are in conflict with Lufthansa’s namesake core airline and its cargo division over pensions.The union’s members declared their readiness to strike in a ballot last year to pressure the company into granting more generous retirement benefits.Talks have since resumed but have been intermittent and without result.Lufthansa, which has described its core airline as “problem child”, says there is no financial leeway for the demands.Separately, the UFO union of flight attendants called on its members at Lufthansa’s CityLine to strike over the planned shutdown of its flight operations and “the employer’s continued refusal to negotiate a collective social plan”.