The Instagram accounts of several Islamic Revolutionary Guard Corps (IRGC) commanders have been blocked with the photo-sharing website saying it was complying with US sanctions, Tabnak news website has reported.

The US on April 8 moved the IRGC to its list of foreign terrorist organisations (FTOs). Washington has never before placed an entity of a foreign government on the list. The unprecedented step has raised fears that the Trump administration is laying the groundwork for military action against Iranian armed forces.

Tabnak said Instagram blocked the accounts of Major General Mohammad Ali Jafari, Major General Mohammad Bagheri and Major General Qassem Soleimani, head of the IRGC Quds force that runs operations outside of Iran. The English-language profiles of Supreme Leader Ayatollah Ali Khamenei's supporters were also blocked.

Contacted by AFP, an Instagram spokesperson said it was operating "under the constraints of US sanctions laws".

In a statement to the BBC Persian service, Instagram said: “We operate under the constraints of US sanctions laws. We work with appropriate government authorities to ensure we meet our legal obligations, including those relating to the recent designation of the IRGC.”

Iran's Telecommunications Minister Mohammad-Javad Azari Jahromi appeared to be referring to Instagram's move with a tweet on April 16.

"When you tear out a man's tongue, you aren't proving him a liar, you're only telling the world that you FEAR what he might say," he wrote on Twitter.

Facebook, Twitter and the Telegram messenger service are officially banned in Iran, meaning Instagram is the only major social media service accessible in the country without the use of a virtual private network, or VPN, to bypass censorship.