The take-off of a German flight to Tokyo was delayed after two dozen Japanese tourists on board fell ill with violent stomach cramps, German police said.

Shortly before take-off Saturday afternoon, the Airbus A340 carrying some 300 passengers returned to the airport terminal in Berlin after the tourists complained of stomach pains and nausea, said a police statement.

The 23 people stricken by the mystery illness, part of a group of some 80 tourists on an organised trip to Europe, were taken to nearby hospitals.