Russian police have arrested four gay rights activists protesting in St. Petersburg on the opening day of the 2014 Sochi Winter Olympics.

During Friday's protest, four gay activists unfurled a banner quoting the Olympic Charter's ban on any form of discrimination. The protesters, who gathered on St. Petersburg's Vasilyevsky Island, were quickly rounded up by police, according to Natalia Tsymbalova, a local lesbian, gay, bisexual and transgender activist.

Olympic Charter:

"The practice of sport is a human right. Every individual must have the possibility of practicing sport, without discrimination of any kind and in the Olympic spirit, which requires mutual understanding with a spirit of friendship, solidarity and fair play."

Fundamental principles of Olympism

Police refused any immediate comment.

A Russian law banning gay "propaganda" from reaching minors has drawn strong international criticism and calls for boycott of the Sochi Games from gay activists and others.

Russian law also bans any unsanctioned protests and violators may face fines or prison sentences.

Russian President Vladimir Putin has said sports should take centre stage during the Winter Olympics and not debate over gay rights. 

In a meeting with Dutch Prime Minister Mark Rutte on Friday ahead of the opening ceremony of the 2014 Games, Putin said the focus should now turn to the Olympics. 

In a tweet from his official Twitter account, Rutte says he "Expressed the concerns of the Dutch government and populace about human rights and specific rights of LGBTs (lesbians, gays, bisexuals, and transgenders) in Russia."