ISNA news agency did not give a reason for the government ban on the service which lets people send encrypted messages and has an estimated 40 million users in the Islamic Republic.

The order came days after Russia - Iran’s ally in the Syrian war - started blocking the app in its territory following the company’s repeated refusal to give Russian state security services access to users’ secret messages.

Iran’s government banned “all state bodies from using the foreign messaging app,” according to ISNA.

Khamenei stopped using Telegram on Wednesday “in line with safeguarding national interests and removing the monopoly of the Telegram messaging app,” state media reported.

The Supreme Leader has a strong presence on social media, even on Twitter and Facebook that are blocked in Iran. His office updates the accounts with photos and his latest speeches.

Telegram, set up by a Russian entrepreneur and ranked the world’s ninth most popular mobile messaging app, has been widely used by Iranian state media, politicians and companies.

A judicial official said this week that Telegram and other foreign messaging services could only operate in Iran if they got permission from the government and saved users’ data inside the country.

Iran temporarily blocked the service in January as security forces sought to contain anti-government protests in more than 80 cities.

Many Iranians kept accessing Telegram then, using virtual private networks (VPNs) and other tools to bypass government filtering.

The service is widely used in countries across the Middle East and the former Soviet Union.