Streets flooded with protesters in various cities and towns across the United States again on Sunday as mostly nonviolent demonstrations over racial injustice and police violence, triggered by the killing of George Floyd in Minneapolis, continued for a third week.

The events were dramatically different from the previous weekend, that saw police applying excessive force against protesters, using teargas and steel sticks, and a non-violent crowd cleared in military-style action in a Washington DC park Monday ahead of US President Donald Trump's photo opportunity.

Demonstrators filled the streets of the country's capital demanding an end to brutality and racial injustice by police. At the Lincoln Memorial and at the White House, they braved the heat, wore masks and chanted in unison. Huge groups attended rallies in Los Angeles, Philadelphia and Chicago that were mostly peaceful protest. Meanwhile hundreds lined up for a public viewing of Floyd's casket in Raeford, North Carolina.

Floyd, an unarmed black man, died in the hands of a police officer in Minneapolis on May 25. Video showed the white police officer kneeling on Floyd's neck for almost nine minutes while he is forcibly pinned on the ground. Police Officer Derek Chauvin was discharged and charged for murder. Also, three other officers on the scene were dismissed and charged with helping and encouraging.

There were also massive anti-racism protests in a number of other nations. In the United Kingdom, the Parliament Square in central London was packed with people following government appeals to avoid mass meetings for fear of coronavirus spreading.

Massive marches have also broken out across the world including Australia, with hundreds of thousands of demonstrators in their own countries calling for an end to racism and police violence.

People staged a demonstration in front of the US embassy in Hong Kong on Sunday, holding up images of Floyd and signs of Black Lives Matter. Massive crowds have also taken to the streets throughout France, Germany and Italy.

Floyd's murder has triggered 12 nights of sometimes uncontrolled mayhem despite city enforced curfews and complaints of police brutality against demonstrators.

More US cities reported on Sunday that they were removing or easing their curfews, with Philadelphia and New York - which saw late-night unrest earlier in the week - joining Buffalo, Atlanta and Chicago.

New York City mayor Bill de Blasio announced that after two days of relatively calm protests, he was canceling the city's curfew with immediate effect. "We saw the very best of our town yesterday and last night," de Blasio said in a tweet, as quoted by Richard Luscombe and Vivian Ho of The Guardian.