On Monday, an opposition activist who featured on the list was hospitalized after being assaulted by unknown men outside of his home. The attack was the latest in what appears to be an intimidation campaign against activists in Russia's second largest city ahead of March’s presidential elections.

A target list featuring the personal data of dozens of activists has reportedly been circulating Russian social media, an opposition politician in St. Petersburg has warned.

A social network page calling itself the “Gallery of Unique People” has been posting the photographs and home addresses of prominent activists since last fall, local opposition deputy Boris Vishnevsky wrote in an article for the Novaya Gazeta newspaper on Wednesday.

The politician said that at least four activists on the list had been physically assaulted in recent weeks.

“All of them have been the victims of criminal attacks that led to serious bodily harm,” Vishnevsky wrote.

He said that the disclosure of personal data constituted a “gross violation” of privacy rights and asked the Investigative Committee to open a criminal case.

“Unfortunately, I’m not certain these measures will be taken, judging from previous practice,” Vishnevsky said, citing similar attacks on activists following personal data leaks in 2016.

Vishnevsky noted that the websites that leaked activists’ information preceding the last wave of attacks had been traced back to Yevgeny Prigozhin, a Kremlin-linked businessman charged last week with conspiring to interfere in the 2016 U.S. presidential election.

“I don’t presume to say that Prigozhin is also involved with this site,” Vishnevsky said.

“But it’s obvious that all sites containing blacklists are performing the very same dirty function,” he added.