Russian police on Wednesday searched the Saint Petersburg offices of jailed Kremlin critic Alexei Navalny and detained his top aide Lyubov Sobol and spokeswoman Kira Yarmysh, his allies said, ahead of nationwide protests in his support.

The morning police raids came ahead of protests planned in more than 100 cities across Russia on Wednesday evening in support of the hunger-striking Navalny, who is protesting his lack of medical treatment in prison.

-Searches were carried out from the very morning- his team in Saint Petersburg said on Twitter.

-They have already come for the office's cameraman, several volunteers and activists.-

Sobol's lawyer Vladimir Voronin said on Twitter that police had pulled her out of a taxi.

-According to her, she was detained by many uniformed officers- he wrote.

He later said she was taken to a police station but was being kept in a police wagon.

Yarmysh retweeted her lawyer saying that she was "just detained at the entrance of her building".

The independent monitor OVD-Info said Wednesday that police had conducted searches and detained activists in at least 20 cities across the country.

The police raids also come ahead of Russian President Vladimir Putin's annual state of the nation address, which he is set to deliver at 12:00 (0900 GMT).

Police have issued warnings against joining Wednesday's rallies in support of Navalny, saying they are illegal gatherings.

More than 10,000 people were detained during demonstrations in support of the Kremlin critic in late January and early February.

The opposition figure was arrested on arrival to Russia in January from Germany, where he had spent months recovering from near fatal nerve toxin poisoning.

He is serving two-and-a-half years in a penal colony for violating parole terms on old fraud charges he says are politically motivated.