However, the Vietnam Airlines official recommended that transit-passengers through Frankfurt should check thoroughly if any other carriers might be affected by the strike. As the strike has spread to six airports - Munchen, Frankfurt, Düsseldorf, Cologne/Bonn, Dortmund and Hannover, the Frankfurt-based Lufthansa airline had to cancel nearly 900 flights on April 27, affecting around 87,000 passengers. Munchen airport was hardest hit, with only 90 flights operated during the day while 545 flights were cancelled.