Iran has given foreign social media sites one year to transfer data they hold on Iranian users inside the country.
"Foreign social media active in the country must transfer to Iran all the data they hold on Iranian citizens into the country in order to ensure their continued activity," Iran's Supreme Council of Cyberspace said in comments carried by state media.
The new requirements are expected to affect the instant messaging app Telegram, which has more than 20 million users inside Iran.
Iran blocks social media websites like Facebook and Twitter, and censors others, although Iranian users can gain access through certain software.
