MOSCOW, May 6, 2008 (AFP) - Anti-Kremlin campaigners were to hold a protest rally in central Moscow on Tuesday despite police warnings, a day ahead of the inauguration of Dmitry Medvedev as Russia's new president.

'I definitely do not recommend that people come today to an event that is being organised by provocateurs,' Vladimir Pronin, head of Moscow's police force, was quoted by Interfax news agency as saying.

'The majority of Muscovites do not want law and order to be threatened. Muscovites are preparing for a sacred day -- Victory Day, and a great political event -- the inauguration of a new president,' Pronin said.

The rally has not been officially authorised and is being organised by The Other Russia, an opposition group headed up by former chess legend turned leading anti-Kremlin campaigner Garry Kasparov, who was expected to attend.

The rally, which was due to start at 6:00 pm (1400 GMT), will protest against Medvedev's election in a vote that The Other Russia said was 'a farce' that gave Russians no real choice about the country's political future.

Organisers said earlier they wanted protesters to march on the Kremlin.

Kasparov was detained and jailed for five days during a similar rally in Moscow in November 2007, just before parliamentary elections that were won overwhelmingly by President Vladimir Putin's United Russia party.

Several leading Russian rights groups, including the Moscow Helsinki Group and For Human Rights, on Tuesday issued an open letter to Moscow's mayor Yury Luzhkov asking him to authorise the protest.

Meanwhile 17 opposition activists told AFP they were being prevented by police from coming out of their apartment in Moscow to attend the rally. The claim could not immediately be confirmed by police.