People demand free elections to the Russian capital's city legislature in Moscow. (Reuters)

Hundreds of people took to the streets of central Moscow on Saturday to demand free elections to the Russian capital's city legislature, defying a ban which has been enforced with violent detentions during previous protests.

Weeks of demonstrations over elections for the Moscow city legislature have turned into the biggest sustained protest movement in Russia since 2011-2013, when protesters took to the streets against perceived electoral fraud.

Chanting "Russia will be free!" and "This is our city!", up to 2,000 protesters marched through one of Moscow's thoroughfares.

"...If we stop going out (and protesting) there will be no hope left at all," said protester Alexandra Rossius, 23.

"We must show the authorities we are not just going to give up and accept the fact that innocent people are being jailed and elections are being stolen."