Police bomb disposal experts were called in late on Wednesday afternoon to defuse the 250 kilogramme aerial bomb that was discovered by labourers in a northern section of the airport, Berlin airports spokesman Ralf Kunkel said.
Operations were suspended just before 6:00 pm "for safety reasons," Kunkel said, resulting in five cancellations and the diversion of about 20 incoming flights to Berlin's smaller Schönefeld Airport.
More than 60 years after the end of World War II, weapons recovery remains an important task for police throughout Germany. Allied forces dropped more than 2.7 million tonnes of explosives across Germany during the war. Some of the ordnance did not explode and has become increasingly dangerous with time and corrosion.
Entire neighbourhoods are frequently evacuated for bomb removal, and most are safely defused. Construction and road workers are trained to call emergency services the moment they suspect they've found unexploded ordnance, but accidents still occasionally happen.
In 1994, three construction workers were killed and eight bystanders injured when an unexpected bomb detonated, tearing through nearby buildings and cars in Berlin. In 2006, a road worker was killed near Frankfurt when his excavator hit a bomb.