Law enforcement officers have searched the Chelyabinsk offices of opposition leader Aleksei Navalny, activists reported on February 13.

The activists said on Twitter that the search took place while nobody was present at the offices in the Urals city.

“We came to the headquarters and found this,” the activists tweeted together with several pictures of the ransacked office. “The premises were raided while we were working remotely,” they said.

The 44-year-old Navalny, a staunch critic of Russian President Vladimir Putin, was arrested on January 17 after returning to Russia from Germany where he had been treated for a nerve-agent poisoning he says was ordered by Putin. The Kremlin denies it had any role in the poison attack against Navalny.

Tens of thousands of Russians took part in street rallies on January 23 and 31 in protest at Navalny’s detention, which sparked outrage across the country and much of the West.

In a change in tactics from mass street rallies that resulted in thousands of arrests, Navalny’s team has called on people across Russia to switch on their mobile-phone flashlights for 15 minutes beginning at 8 p.m. local time on February 14 — shining the light into the sky from courtyards and posting pictures of the protest on social media.

In an attempt to limit the planned February 14 flashlight-protest, Russia’s federal media regulator ordered media outlets, including RFE/RL’s Russian Service and Current Time TV, to delete all reports about the event.

The official order from Roskomnadzor was received by media groups on February 12.

It says Russian authorities consider any reporting about the planned flashlight protest to be a call for people to take part in an unsanctioned public demonstration and mass disorder.

Roskomnadzor’s order was also sent to online newspapers Meduza and Open Media, and the TV-2 news agency in the Siberian city of Tomsk.

Navalny’s team in Tomsk said they were also warned by the city prosecutor’s office on February 12 that they could be held liable for staging an unsanctioned protest action.

Telegram channel Baza reported on February 13 that in Bryansk, 379 kilometers southwest of Moscow, students were banned from using flashlights on the premises of the local university on the day of February 14.

Leonid Volkov, director of Navalny’s network of teams across Russia, announced the change of tactics on February 9 in response to police crackdowns against mass street demonstrations that have led to tens of thousands of arrests across Russia.

The “flashlight” protest is a tactic similar to what demonstrators have been doing in neighboring Belarus following brutal police crackdowns targeting rallies against authoritarian ruler Alyaksandr Lukashenka.

Volkov says it is a nonviolent way for Russians to show the extent of outrage across the country over Navalny’s treatment without subjecting themselves to arrests and police abuse.

Police cracked down harshly on the demonstrations, putting many of Navalny’s political allies behind bars and detaining thousands more — sometimes violently — as they gathered on the streets.

A Russian court on February 2 ruled Navalny was guilty of violating the terms of his suspended sentence relating to an embezzlement case that he has called politically motivated.

The court converted the sentence to 3 1/2 years in prison. Given credit for time already spent in detention, the court said Navalny must serve another 2 years and 8 months behind bars.

That prompted fresh street protests across the country. But Volkov called for a pause in street rallies until the spring — saying weekly demonstrations would only result in more mass arrests.

With reporting by RFE/RL’s Russian Service, Meduza, TV-2, Dozhd, and Znak