Police in Munich were forced to take action after a couple caused a stir by performing a sexual act on an underground train. On 13 October, afternoon commuters on the U5 line were left stunned by the young couple.

One passenger aboard the train spotted the pair, aged 19 and 20, kissing on the busy commuter route, but was shocked when the woman started to orally satisfy her male partner.

A 46-year-old female passenger then traded insults with the pair after trying to get them to stop. Security and police were forced to intervene at Munich's Max-Weber-Platz U-Bahn station, TheLocal reported.

The couple were arrested by police and now face charges for public nuisance and verbal abuse to fellow passengers.

Officials at the underground network said that this wasn't the first time that they had been called in to break up sexual acts.

An employee at the Munich Transport Corporation, Edward Imblon, said that in the 30 years he has worked for the underground network, there have been "two or three" occasions where such acts have had to be dealt with.

But he added that such incidents were rare and the counts of abuse that their staff face on a daily basis over delays or cancellations is more of a concern to the network.

"Verbal attacks have become part of the daily business. You need a thick skin for this job," said Imblon.