Russian authorities on Friday searched the homes of three lawyers representing imprisoned opposition leader Alexei Navalny and detained one of them, the politician’s allies said.

The move against his lawyers is an attempt to “completely isolate Navalny,” his ally Ivan Zhdanov said on social media. Navalny has been behind bars since January 2021, serving a 19-year prison sentence, but has been able to get messages out regularly and keep up with the news.