MOSCOW - Russian police raided the homes and offices of supporters of opposition leader Alexei Navalny in 43 cities on Thursday, his close allies said.

So far, more than 200 raids have taken place across Russia from Vladivostok on the Pacific to Krasnodar in Russia's south.

Police have also searched the home of Sergei Boyko, a Navalny associate who came second with nearly 20% of the vote in the mayoral election in Russia's third-largest city of Novosibirsk last Sunday.

Navalny in a video message mocked authorities for the raids, comparing them to a crackdown on a drug cartel and vowed to keep up his work.

“We are not going to stop our work, don't you worry about that,” he said, adding that authorities on Tuesday blocked bank accounts linked to Navalny's political aspirations.

Police appear to be targeting those who were part of Navalny's 2018 presidential election campaign. Though Navalny wasn't allowed to run, his supporters in local election headquarters in dozens of Russian cities have grown in force, investigating high-level corruption and mobilizing supporters for opposition rallies.

Many of his allies in the regions ran in local elections last Sunday and monitored the voting, documenting wide-spread violations in some regions like St. Petersburg. They have followed his lead in harnessing new technology including YouTube live broadcasts and slickly produced video investigations.

“We're obviously talking about an attempt to hamper the operations of our regional network,” Leonid Volkov told The Associated Press.

He said he expected police to confiscate equipment and described the raids as a “robbery attempt,” estimating the damage at several million rubles (over $15,000).

Volkov said the raids were linked to their successful election strategy in Moscow which cut the presence of pro-government candidates in the city legislature by a half. Police turned up at all of Navalny's chapters at 6 a.m. Moscow time despite the vast time difference across the country, which points to a co-ordinated effort, Volkov said.

Respected election monitoring group Golos also reported that homes of three of its regional co-ordinators have been raided. It said in a statement that the three people were training election monitors before the Sunday vote.

Golos condemned the police actions as “an attempt of pressure and intimidation of public monitors.”