Flights to Frankfurt and Muscat from Abu Dhabi and Dubai operated by Lufthansa are cancelled because of a four-day strike by pilots, which began today. The strike came about when management at the German airline failed to reach an agreement with the Vereinigung Cockpit union over management decisions that include the type of aircraft used by the airline and its European subsidiaries. Industrial action will continue until February 25. Christoph Meier, a spokesperson for the company in Africa and the Middle East, said: "We are certain the strike will not end any later than Thursday. Hopefully it will end earlier." Two thirds of the airline's 1,800 daily flights have been grounded by the strike, he added. The airline was unable to say exactly how many travellers in the UAE the strike would affect. It has told passengers they can rebook for free for flights later in the week that are unaffected by strike action or get a refund. Lufthansa operates several flights out of Abu Dhabi and Dubai. A flight between Muscat, Abu Dhabi and Frankfurt which runs six times a week has been cancelled. Also, daily flights between Dubai and Frankfurt have come to a halt. Trips between Dubai and Munich are operating as scheduled. Mr Meier said the airline had chosen to cancel flights that were either under booked, required more staff, or not part of the airline's core network. "There are a number of influencing factors. First of all we have to keep operating the basic network and most of our high demand trunk routes," he said.