Police have launched a wave of investigations against young people, mainly women, in recent weeks for taking partially nude or sexually suggestive photographs next to Russian landmarks. At least four cases have been reported over the past week of police detaining, investigating or jailing Russians for photographs that have been posted online in front of the Kremlin walls, St Basil’s Cathedral, St Isaac’s Cathedral in St Petersburg and an “eternal flame” dedicated to the history of the second world war. One couple has been sentenced to jail for 10 months for taking a photograph suggestive of oral sex in front of the distinctive onion domes of St Basil’s Cathedral in Moscow. Ruslan Bobiev and Anastasia Chistova, who wore a police jacket in the picture, were found guilty last week of “insulting believers’ feelings” – marking the first time that those charges had led to prison time. Bobiev, a blogger from Tajikistan, was also ordered to be deported from Russia. Other women have been detained for flashing their buttocks or breasts in front of public landmarks or police stations in various cities including St Petersburg and Yekaterinburg in cases that stretch back to August. Several of those investigated said they were not responsible for the material being put online. The cases, which have often been pursued by conservative activists who have complained to the police, mark another step forward in the policing of social networks and the willingness of the authorities to use severe punishments against apolitical Instagram stars and influencers. While a judge chose to jail two members of the punk protest group Pussy Riot in 2012 for two years after a performance in a Moscow cathedral, many of the recent cases are far less politicised, and appear to be driven by greater attention to Instagram accounts used by ordinary Russians. One woman, an adult actress and model on OnlyFans, said she was a “patriot” after she was sentenced to 14 days behind bars for a picture showing her buttocks near the Kremlin walls. Another, who was briefly jailed for a similar photograph in front of St Isaac’s Cathedral in St Petersburg, was only released because she had a school-aged son. On Friday, a model publicly apologised after reports that an investigation was opened over a three-year-old photograph with her kissing another woman in front of the “eternal flame” near the Kremlin walls. The flame is a monument dedicated to Soviet dead in the second world war. “Please accept my honest apologies for the video that was created three years ago,” she wrote. “It was made without the goal to offend or defile.”