Washington, Jan 21 : Violent anti-Trump protesters attacked police, set fires and smashed windows of stores and businesses but riot-geared security forces successfully kept them away from the Capitol Hill swearing-in ceremony and the parade to the White House on Friday.

Masked rioters threw rocks and concrete blocks at police, injuring at least six of them, and attacked Trump supporters marring what was billed as a peaceful transfer of power from a Democrat to a Republican and held up as an example to the world.

A car was set ablaze and at several places trash was piled up and set on fire. Newspaper vending boxing were thrown around and bus stands damaged.

Police retaliated with pepper spray and stun grenades, which are non-lethal and produce flashes of light and explosive sound. Police arrested 217 people in connection with the riots.

Before the swearing-in ceremony started, protesters disrupted some checkpoints preventing people from entering.

More than 28,000 police and other security personnel were deployed around the city.

There were no riots when Barack Obama was sworn-in. Democratic Party leaders did not come out with calls for peace and Republicans ignored it, although it could come in handy as ammunition for them and Trump.

While the riot was going on, President Donald Trump said in his speech after the swearing-in that the "American carnage" in the cities must end right now. But he was referring to the criminal violence that claims thousands of lives, rather than the riot.

There were also peaceful protests. A group of people stood up at the ceremony with shirts that spelled "R-E-S-I-S-T". They were removed peacefully from there.

During the parade from the Capitol to the White House, a group of protesters stood near the Trump International Hotel on the route and jeered him as he went by.

Riots mar transfer of power in US from Democrats to Republicans