German carrier Lufthansa is to warn international passengers, men in particular, about the dangers of landing at airports on the Rhine tomorrow, the day women cut men's ties off and compensate them with an unexpected kiss.

The airline said it would make announcements on its flights landing at Cologne/Bonn and Dusseldorf airports to prepare passengers for potentially traumatic encounters on arrival at the airports and later the cities themselves.

Tomorrow falls six days before Ash Wednesday, which marks the start of Lent, and is traditionally the day in the Catholic parts of Germany when "Weiberfastnacht", one of the high points of the carnival season, is celebrated.