Passengers were ordered to keep their hair under control while riding the subway in Bangkok, Thailand.

The BTS Skytrain urged commuters to tidy up their hair to avoid flicking it into other people's faces during rush hour.

The skytrain operator posted a bizarre warning and illustration on its Facebook page, instructing passengers to 'firmly hold the end of your long hair when you turn your face, walk past other passengers and enter or leave the train'.

The image shows one rider's long locks slapping another woman's face as she whips her head around inside the train car.

The BTS said the advisory was prompted by locals' complaints. Some passengers had feared that hair being waved around 'could spread germs'. Others complained that they had been touched by another person's locks.

Thailand has one of the world's highest rates of obedience for mask-wearing, which has been sparked by the recent pandemic.

A survey from the country's Department of Health found that 94 per cent of Thai people said they would carry on wearing face masks in public, despite the mandatory rule being scrapped. Only six per cent said they would ditch the environmentally harmful accessory.

The Public Health Ministry advised people to continue to wear masks in crowded or poorly ventilated places.