CHICAGO • Friends and relatives of two African-Americans fatally shot by police in Chicago have issued an emotional plea for justice, calling the incident the latest proof that the city's officers are far too quick to use deadly force.

Family members held a press conference following Saturday's police shootings of Ms Bettie Jones, 55, a mother of five, and 19-year-old engineering student Quintonio LeGrier.

Both were shot and killed after police were called to a private residence in response to a call about a domestic dispute.

News reports said the teen struggled with mental health issues, and had been threatening his father with a baseball bat.

Shortly after arriving on the scene, police opened fire, striking Mr LeGrier, who they said was charging down the stairs carrying the bat.

Ms Jones, Mr LeGrier's downstairs neighbour, who opened the door for officers as they arrived, was struck by a police bullet and died on Saturday in hospital.

Separately, police fatally shot another man within hours of the other two shootings, according to news reports, some of which said the man was armed but had dropped his weapon and had his arms raised when police opened fire.

Many people in Chicago - already reeling from other recent incidents in which the police are said to have been too ready to pull the trigger - condemned the shootings.

"This needs to stop," Mr LeGrier's mother, Ms Janet Cooksey, told reporters on Sunday.

"No mother should have to bury her child, especially under these circumstances. The police are supposed to serve and protect us," Ms Cooksey said through tears.

She added at the press conference that her son was "a good child" and an honour student.

"Seven times my son was shot, once in the buttocks - that showed he was turning away," said the grieving woman said.

While a debate plays out over race and policing in cities across the United States, Chicago police were already under significant scrutiny after the release last month of a video showing a black teenager, Laquan McDonald, being shot 16 times last year by a white police officer. Most of the shots were fired as the boy lay motionless on the ground.

The police meanwhile, in a terse statement, expressed regret over the shooting of Ms Jones, which they said was a tragic accident.

AGENCE FRANCE-PRESSE, NEW YORK TIMES