Hundreds of people have marched in the Turkish Mediterranean city of Antalya on Sunday, in protest of a G-20 summit that is underway in a nearby seaside resort. Police detained four protesters who wanted to deliver a letter to the leaders.

A group of some 500 youths belonging to a Turkish nationalist association marched in Antalya, holding up effigies of U.S. President Barack Obama and denouncing U.S. interventions in the Middle East.

Hundreds of members of Turkish left-wing groups and trade unions later held another protest denouncing the organization which gathers the world's wealthiest economies.

They marched in central Antalya carrying a banner that read in Turkish and in English: "Killer, colonialist, imperialist war organization G-20 get out!"

Separately, members of Turkey's ethnic Uighur community also gathered in the city to protest China's treatment of the Muslim minority. Chinese President Xi Jinping is among the participants.

All of the protests took place some 25 miles away from the summit venue under heavy riot police presence.

Earlier, police detained four protesters who wanted to walk to the venue of the G-20 summit to deliver a letter to participants.

The state-run Anadolu Agency said police blocked the four protesters from marching toward the venue, prompting them to hold a sit-down demonstration. Police detained the group and took them to a sports center that has been turned into a temporary detention center for protesters, the agency reported.

The summit is expected to be dominated by discussions about how the G-20 nations will respond to the Paris attacks.