The authorities in Namibia have condemned tourists who posed naked in one of the country's top attractions - the Big Daddy dune in the Namib desert.
Visitors told a local newspaper they were shocked by the behaviour and called for action against the tourists.
The unnamed foreigners might be blacklisted from entering any of Namibia's parks, a spokesperson from the tourism ministry told local media.
Photos and a video have been widely shared, sparking sharp reactions.
Kenneth Nependa, vice-chairperson of the Federation of Namibian Tourism Associations, told the Namibian Sun news website that the behaviour risked attracting tourists "who think anything goes in Namibia".
"It is very sickening and it really [creates] a bad image for Namibia," Mr Nependa said, adding that the Big Daddy dune was not just a relaxing place for tourists but for families too.
It is not clear who took the photos and the video of the three male tourists, who are seen stark naked in the sandy dune, next to their clothes.
The authorities did not immediately respond to BBC enquiries about the identity of the tourists.
Romeo Muyunda, the spokesperson for the Ministry of Environment, forestry and Tourism, termed the behaviour "extremely shocking" in a statement cited by local media.
He said it was public indecency punishable by Namibian law.
"We appeal to that section of tourists to summon the conscience so that they do the right things," Mr Muyunda added.
The tourists had left the country by the time authorities received the reports, he said.
He appealed to Namibians to report violations of park regulations immediately for swift action.
But some social media users said there was "nothing wrong with sunbathing".
"Why are they in trouble? They bothered no one," an X user posted.
The Big Daddy dune is one of the three largest dunes in Namibia's enormous Namib-Naukluft National Park, one of the largest in the world.
The dunes are popular with tourists who hike to the top to have a stunning view across the crests.