Swedish pilots flying for SAS, the owner of Scandinavian Airlines, extended a walkout in a pay dispute to a fourth day, joining cockpit crews at Air France-KLM in hitting travel the opening weekend of the Euro 2016 soccer tournament.

SAS canceled 230 domestic Swedish and European flights on Monday, bringing the total to 649 since Friday, as 400 members of the SPF union continue walkouts in a two-month-old conflict about salary and working hours, the carrier said in a statement. Flights operated by Danish and Norwegian pilots, partner airlines and long-haul services will operate, the airline said.