Dutch police were called out to deal with over 28,000 incidents involving drink and drugs in the first six months of this year, the AD reported on Tuesday.

The number of drink and drug-related call-outs is up 6% on the same period last year but overall, police have had to deal with 10,000 fewer reports of nuisance, the paper said.

Neither the police nor experts can explain the shift, the AD said, although the weather may have led to more people being outdoors and overindulging in public. This spring there were almost twice as many summery days as normal and little rain.

The only part of the country where there were fewer reports of drink and drugs-related problems was Limburg, where the total fell 4%. In Groningen and Flevoland, by contrast, reports rose 20%.

Beach resort Zandvoort had the worst figures per head of the population, followed by Groningen and Arnhem.