One person was killed and another wounded in a shooting at a Black Lives Matter rally in the US state of Kentucky, police said.

The incident Saturday took place at Jefferson Square Park in the center of Louisville where protestors have gathered for weeks over the killing of African American woman Breonna Taylor. 

Her death in March helped fuel a campaign against racism and police brutality in the United States that has since spread across the globe. 

Louisville Metro Police Department said officers were called to the park at around 9:00 pm.  

"Calls then came in that Sheriff's Department personnel were in the park performing life-saving measures on a male who eventually died at the scene," the department said on Twitter. 

Soon after another person was shot across the street at the city's Hall of Justice, police added. 

It was unclear if there was more than one shooter and authorities have yet to release any details of the victims. 

Louisville mayor Greg Fischer said he was "deeply saddened by the violence."

Before the shooting, Fischer had urged counter-protesters to stay away from the park, after local newspaper Louisville Courier Journal reported that "armed patriot groups" were planning on confronting the demonstrators. 

Louisville has seen especially passionate Black Lives Matter protests due to the police killing Taylor in her own apartment.

The 26-year-old emergency room technician was shot dead after police barged into her home, alleging that drug dealers had used the apartment to receive packages.

The case helped trigger fresh waves of anger in the United States over racial injustice and police brutality.

Those protests expanded dramatically after the May 25 killing of George Floyd, an unarmed black man who died in Minneapolis after a white police officer pinned his knee to Floyd's neck for more than eight minutes.

1-year-old killed in drive-by shooting
A one-year-old boy was killed and his mother wounded in a Chicago drive-by shooting that has stunned authorities accustomed to rampant gun violence in America's third-largest city. 

The 22-year-old mother was driving home on Saturday afternoon when the attacker pulled up next to her car and fired around eight shots, striking the infant in the chest and grazing her head, police said. 

"This is happening far too often," Chicago police operations chief Fred Waller told reporters near where the shooting took place in the city's south. "When is this going to stop? When are we gonna say enough is enough?"

The incident came a week after the shooting death of three-year-old Mekhi James, who died in similar circumstances while traveling in a car with his father on the city's west side. 

"We'll catch the person that killed that three-year-old. We'll catch the person who killed this kid," Waller said.

Chicago mayor Lori Lightfoot and police superintendent David Brown asked the city's residents to speak up if they had information on Saturday's attack. 

"We ALL need to be outraged by the violence we are seeing in our city. This baby, and all of our residents, deserve better," Brown said.

No arrests have been made and police are continuing to investigate both cases.

Two killed in Wal-Mart shooting
At least two people were killed and four wounded in a shooting at a Wal-Mart distribution center in California, US media reported Saturday.

A local newspaper, the Record Searchlight, quoted a witness who said he heard what sounded like gunfire from a semi-automatic weapon at the facility in the city of Red Bluff.

The Searchlight and other media including CNN cited hospital officials on the toll.

Red Bluff city Rick Crabtree manager told CNN that a car rammed the facility around 3:00 pm local time, causing a fire which he said was not significant.

"There was an active shooter, he was shot, last I heard he was on his way to the hospital," Crabtree was quoted as saying.

A Wal-Mart spokesman told CNN they were aware of the situation and working with law enforcement to investigate, but could offer no further details.