The world’s biggest beer festival has recorded its lowest turnout for 15 years amid heightened security fears, while at the same time experiencing an increase in reported sex crimes.

The Oktoberfest in Munich, Germany had around 5.6 million visitors this year, down 300,000 since last year and the lowest number since just after the September 11th 2001 terror attacks, according to FAZ.

The drop in the number of attendees follows a series of attacks in the German state of Bavaria.

In July, German-Iranian student David Ali Sonboly went on a shooting spree in Munich, killing nine people at a shopping centre before turning the gun on himself.

In the same week, an Afghan migrant attacked a train in Würzburg with an axe, injuring at least four people, and a failed asylum seeker blew himself up at a bar in the town of Ansbach, injuring 12 people and killing himself.

However, despite an overall fall in crime at the festival, the number of reported sex crimes increased this year from 21 to 31.

The group “Safer Wiesn for Girls and Woman” also said 215 women came to security checkpoints for help this year compared to 197 last year, of whom 18 reported suffering violence.

A number of large-scale public events have reported an increase in sexual assaults since the massive influx of migrants began entering Europe last year.

The most notorious example was the New Year’s Eve attacks in the German city of Cologne, in which gangs of mainly North African migrants committed mass sexual assaults against women revellers.

Police received over 1,500 complaints of sexual assault, mugging, pickpocketing and even rape, although it took the local government six months to admit the majority of perpetrators were recently arrived migrants.

Figures showed that 70 per cent of the suspects had been in Germany for less than a year, despite repeated denial by authorities.