The North Korean authorities have reportedly stepped up a crackdown on “non-socialist” behaviour, including unapproved hairstyles, ahead of the 70th anniversary of the country’s founding in September.

Youth groups affiliated with the regime are said to have been deployed across the country to warn or detain citizens found sporting banned fashions or hairstyles, North Korean sources told Radio Free Asia.

“Inspection units are being dispatched to public areas,” one source said.

"With the approach of the 70th anniversary on September 9 of the founding of the North Korean regime, the Central Committee has given special instructions to root out non-socialist phenomena, such as fashion choices and hairstyles that do not fit the socialist lifestyle,” the source added.

Instructions on what constitutes “non-socialist” behaviour have reportedly been given through lectures at work units and factories, with a specific focus on young people.