Telegram, which has 200 million global users, has been popular in countries including Russia and Iran.
Iranian President Hassan Rouhani has criticised the ban imposed on popular messaging app Telegram by the conservative-run judiciary, saying the move was "the opposite of democracy".
Human Rights Watch on Wednesday hit back at Iran's ‘unjustifiable’ decision to ban the Telegram messaging app, warning Tehran against stifling access to information.
In an usually strong turnout, at least 8,000 people including top opposition leader Alexei Navalny turned up in the centre of the Russian capital, many holding placards and shooting paper airplanes.
The decision came a week after state communication watchdog, Roskomnadzor, filed a lawsuit to limit access to Telegram following the company's repeated refusal to give Russian state security services access to its users' secret messages.
Iran's telecoms minister said on Wednesday that Telegram would only be unblocked if it removed "terrorist" content after the social media app was shut down during this week's protests.