Telegram CEO Pavel Durov has called on supporters across Russia to stage a new protest against the government's efforts to block the popular messaging app.
Durov, who left the country under pressure in 2014 and lives abroad, thanked Russians who threw paper airplanes from their windows on April 22 in support of Telegram.
Telegram’s logo is a paper plane.
"Next action? On Sunday, April 29," Durov wrote on the social network VKontakte on Arpil 23.
On April 16, about a dozen activists threw colored paper planes at the headquarters of the Federal Security Service (FSB) on Moscow's Lubyanka Square, after state media regulator Roskomnadzor started enforcing a court ban on Telegram over its refusal to hand over encryption keys to the FSB.
Telegram has refused to share data, citing privacy concerns, and promised to keep the app running despite the ban.
The move to block Telegram -- which has met with mixed success -- has deepened concerns that the government is seeking to close avenues for dissent as President Vladimir Putin heads into a new six-year term.