"Due to strike action of ground staff at Berlin’s airports Schönefeld and Tegel there is severe disruption of air traffic from 13 March 4 a.m. [03:00 GMT] until 14 March approx. 5 a.m. After the end of the strike action restrictions in air traffic may continue," the operator said in a statement.
The previous strike took place on Friday-Saturday and led to the cancellation of nearly 700 flights.
The ground staff demands a pay increase from 11 ($11.67) to 12 euros per hour.