Continuing strike action by ground staff of the German airline Lufthansa again caused numerous flight cancellations in Germany on Friday. Around 1,000 flights will be cancelled during the course of the day, especially at the Munich and Frankfurt hubs, a company spokesman said on Friday. Only 10 to 20% of the normally scheduled flights will take place. he said. The Verdi trade union intends to continue its industrial action until 7:10 am (0610 GMT) on Saturday morning. Lufthansa expects there to be initial delays and some cancellations on Saturday. Air traffic should then gradually normalize du…