MOSCOW: Russian opposition leader Alexei Navalny was taken from jail to hospital on Sunday after suffering `severe allergic reaction` with swelling of theface and redness to the skin, his spokeswoman said.

The activist is serving a 30-dayjailsentencefor calling a mass protest after authorities blocked prominent opposition candidates from taking part in Moscow city elections.

`The source of the allergic reaction has not been determined,` Kira Yarmysh wrote on Twitter, noting that Navalny had never experienced an allergic reaction before.

`He is currently in the ward under the supervision of police officers. He is being provided with the necessary medical assistance,` she added.

Navalny hoped to stand against President Vladimir Putin in an election last year but was barred because of a fraud conviction he and supporters say was politically motivated.

The 43-year-old has served several short jail sentences over his protest activity.

Two years ago, Navalny had to travel to Spain for surgery after a street attack left him nearly blind in one eye.

Sunday`s hospitalisation came a day after almost 1,400 people were arrested at the demonstration the opposition leader had called.

Leonid Volkov, Navalny`s former campaign manager, said he had a similar reaction after he served a sentence in the same celllast month for violating protest laws.

He rejected talk of a `conspiracy`, calling instead for a `serious inspection` of hygiene standards at the jail, in a tweet posted on Sunday.

In a separate incident on Sunday, Russian activist Dmitry Gudkov, who was among the opposition candidates barred from running in local elections this year, said he had been detained and taken to a Moscow police station. The reason for Gudkov`s detention was not immediately clear, his spokesman Alexei Obukhov said. Russia`s Interior Ministry did not respond to a request for comment on Gudkov`s detention. Obukhov said Gudkov, a former MP who challenged pro-Kremlin initiatives, had been detained as he walked out of a shop near his home, where he had been buying food for the protesters still being held.-Agencies