Thousands attend Floyd's Houston memorial

Erwin Seba
Mourners have come from near and far to pay tribute to George Floyd in his native city of Houston

Thousands of mourners have braved sweltering Texas heat to view the casket of George Floyd, whose death after a police officer knelt on his neck ignited worldwide protests against racism and calling for reforms of US law enforcement.

American flags fluttered along the route to the Fountain of Praise church in Houston, where Floyd grew up, on Monday as throngs of mourners wearing face coverings to prevent spread of the coronavirus formed a procession to pay final respects.

Solemnly filing through the church in two parallel lines, some mourners bowed their heads, others made the sign of the cross or raised a fist, as they paused in front of Floyd's open casket. More than 6300 people took part in the visitation, which ran for more than six hours, church officials said.

Fire officials said several people, apparently overcome by heat exhaustion while waiting in line, were taken to hospitals.

The public viewing came two weeks to the day after Floyd's death was captured by an onlooker's video. As a white police officer knelt on his neck for nearly nine minutes, an unarmed and handcuffed Floyd, 46, lay face down on a Minneapolis street, gasping for air and groaning for help, before falling silent.

The case was reminiscent of the 2014 killing of another African American, Eric Garner, who died after being placed by police in a chokehold while under arrest in New York City.

The dying words of both men, "I can't breathe", have become a rallying cry in a global outpouring of rage, drawing crowds by the thousands to the streets despite health hazards from the coronavirus pandemic.

The demonstrations stretched into a third week on Monday.

As the public viewing unfolded in Houston, Derek Chauvin, 44, the police officer who knelt on Floyd's neck and is charged with second-degree murder, made his first court appearance in Minneapolis by video link. A judge ordered his bail raised from $US1 million to $US1.25 million ($A1.78 million).

Chauvin's co-defendants, three fellow officers accused of aiding and abetting Floyd's murder, were previously ordered held on $US750,000 to $US1 million bond each.

All four were dismissed from the police department the day after Floyd's death.

Unleashed amid pent-up anxiety and despair inflicted by a pandemic that has hit minority communities especially hard, the demonstrations have reinvigorated the Black Lives Matter movement and thrust renewed demands for racial justice and police reforms ahead of the November 3 presidential election.

Protests in a number of US cities were initially punctuated by episodes of arson, looting and clashes with police, deepening a political crisis for President Donald Trump as he repeatedly threatened to order the military into the streets to help restore order.

Democratic presidential candidate Joe Biden met Floyd's relatives for more than an hour in Houston on Monday, according to the family's lawyer, Benjamin Crump.

"He listened, heard their pain and shared in their woe," Crump said. "That compassion meant the world to this grieving family." Floyd was due to be buried on Tuesday.

In Washington, Democrats in Congress unveiled legislation to make lynching a federal hate crime and to allow victims of police misconduct and their families to sue law enforcement for damages in civil court, ending a legal doctrine known as qualified immunity.

The bill would also ban chokeholds and require the use of body cameras by federal law enforcement officers, place new restrictions on the use of lethal force and facilitate independent probes of police departments that show patterns of misconduct.

The legislation does not call for police departments to be defunded or abolished, as some activists have demanded.

Trump pledged to maintain funding for police departments, saying 99 per cent of police were "great, great people".

"There won't be defunding, there won't be dismantling of our police," Trump told a roundtable of state, federal, and local law enforcement officials at the White House.

Biden opposed the movement to defund police departments but supported the "urgent need" for reform, a campaign spokesman said.