(AP Photo/Musa Sadulayev)

MOSCOW - Hundreds of cars circled central Moscow during an opposition demonstration on Sunday to demand that Prime Minister Vladimir Putin allow free elections in Russia.

As they travelled along the wide Garden Ring, which makes a 16-kilometre (nearly 10-mile) loop around the Kremlin, the cars flew the white ribbons and balloons that have become a symbol of the peaceful anti-Putin protest movement. One family held up their little white dog in an open, passenger's side window.

Sunday's demonstration took place two weeks before the presidential election, which Putin is expected to win. Although none of his four challengers poses a serious threat, Putin does need to get a majority of the vote to avoid a runoff.

A similar protest in support of Putin late Saturday drew what police said were 2,000 cars.

Putin's supporters have been trying to counter the opposition protests by showing that they too can bring people out onto the street. Tens of thousands of people are expected to attend a pro-Putin rally in Moscow on Thursday, a national holiday.

The largest protests the country has seen in two decades began in December following a parliamentary election that was manipulated to boost the results for Putin's party.