US police shootings of black men 'deeply troubling' - Obama

US President Barack Obama has said the fatal shootings of two black men by police in as many days are "not isolated incidents" and that all Americans should be "deeply troubled".

He acknowledged that the US had a "serious problem" but called for people to come together as a nation.

Protests have continued since the shooting of Philando Castile during a traffic stop in Minnesota on Wednesday.

It came a day after Alton Sterling was shot dead by police in Louisiana.

The incidents follow a long line of controversial deaths of African-Americans at the hands of the police that has ignited a national debate about the use of lethal force.

President Obama said such fatal shootings were "symptomatic of the broader challenges within our criminal justice system, the racial disparities that appear across the system year after year, and the resulting lack of trust that exists between law enforcement and too many of the communities they serve".

He added: "As a nation, we can and must do better to institute the best practices that reduce the appearance or reality of racial bias in law enforcement."

An elderly white woman, Diana, has driven 40 miles to this quiet middle-class suburb to pay her respects. She was part of the civil rights movement that protested against discrimination, she says, "and it's still going on".

Joe, an elderly man passing round blueberries to protesters gathered outside the governor's mansion, agrees: "It's an indictment of my generation of white people."

The rally is multi-racial and peaceful but black anger is visceral. "He (Castile) lost his life for a broken tail light," spits out one speaker.

"Use your white privilege to help us," admonishes another. A pastor and Iraqi war vet, Thomas, offers this bleak view of the police: "This is the same as a combat zone," he says. "If black people get pulled over we need to position ourselves as prisoners of war and survive the encounter."

Police killings that scar the US

Walter Scott - unarmed and shot in the back as he ran away from an officer in North Charleston, South Carolina, in April 2015. Former officer Michael Slager facing murder charge

Laquan McDonald - 17-year-old was holding a knife but appeared to be moving away from police in Chicago when shot 16 times in 2014. Officer Jason Van Dyke denies murder charge

Michael Brown - 18-year-old shot at least seven times in Ferguson, Missouri, in August 2014, sparking nationwide protests. Officer Darren Wilson cleared of wrongdoing

Eric Garner - died after being placed in a chokehold by New York police while selling cigarettes in July 2014. Grand jury decides against charges, police disciplinary action taken against supervising officer Sgt Kizzy Adonis

Source: BBC