Former Soviet Union leader Mikhail Gorbachev has called for a repeat of Sunday's parliamentary elections, saying the results were tainted by widespread reports of fraud.

"The country's leaders must admit there were numerous falsifications and rigging and the results do not reflect the people's will," BBC quoted Gorbachev, 80, as telling news agency Interfax.

"Literally by the day, the number of Russians who do not believe that the declared election results were honest is increasing," he said.

The ruling party, United Russia, won nearly half of all seats in the parliament, though number was much reduced from previous elections, indicating weakening support for Prime Minister Vladimir Putin, who has declared his intention to run in the presidential elections in March.

Foreign observers of the elections said balloting was padded and manipulated to favor United Russia candidates.

Several thousands of people protested against Putin and the results of Sunday's elections in central Moscow on Monday. Police arrested many, including anti-corruption blogger Alexei Navalny and Solidarity activist Ilya Yashin, who were both jailed for 15 days on charges of obstructing police, the BBC reported.

On Tuesday, police broke up opposition rally on Triumphal Square and arrested 569 protesters, including liberal politician Boris Nemtsov. Police also dispersed demonstrators in St. Petersburg and arrested 230 protesters, while 25 protesters in the southern city of Rostov-on-Don were detained.

There were also pro-Putin rallies, but these were not suppressed.

A big rally calling for honest elections in Revolution Square on Saturday is being organised through Facebook, with 16,000 indicating as of Wednesday that they will participate.