Media playback is unsupported on your device Media caption Mayor Betsy Hodges was interrupted by angry protesters at a news conference about the resignation

A police chief in the US state of Minnesota has resigned after one of her officers fatally shot an unarmed Australian woman.

Justine Damond was killed after she called the police to report a woman screaming outside her home in a quiet suburb of Minneapolis last week.

Police chief Janee Harteau had earlier said it "should not have happened".

The city's mayor accepted her resignation, saying she had lost confidence in Ms Harteau.

Ms Damond's death provoked outrage in her homeland, where Prime Minister Malcolm Turnbull called it "inexplicable" and "a shocking killing".

The 40-year-old yoga and meditation teacher, originally from Sydney, was shot when she approached a police car after reporting a suspected rape.

A lawyer for Ms Damond's family has called it "ludicrous" to suggest the two officers inside had feared an ambush.

Australia waits for answers in US shooting

Speaking at a news conference in Minneapolis shortly before her resignation was announced, Ms Harteau said the killing was "the actions and judgement of one individual".

Media playback is unsupported on your device Media caption Police Chief Janee Harteau held a news conference before her resignation

Officer Mohamed Noor, who shot Ms Damond in the abdomen, has refused to be interviewed by investigators, as is his legal right.

Cameras 'should be active'

Body cameras, which are worn by all Minneapolis police, had not been turned on at the time of the shooting and the squad car dashboard camera also failed to capture the incident.

Chief Harteau said the cameras worn by Officers Noor and Matthew Harrity "should have been activated".

Mayor Betsy Hodges said, in a written statement, that it was unacceptable for body cameras "to fail us when we needed them most".

Image copyright Facebook Image caption Justine Damond with her fiancé, Don

Fred Bruno, the lawyer for Officer Harrity, has said: "It is reasonable to assume an officer in that situation would be concerned about a possible ambush."

However Robert Bennett, who represents Ms Damond's family, said she "was not a threat to anyone".

He told CBS News: "I think that [the ambush fear] is ludicrous. It's disinformation. It doesn't have any basis in fact."

911 calls

On Wednesday, police released the transcript of two separate 911 calls Ms Damond made after hearing screams nearby.

"I'm not sure if she's having sex or being raped," she told the police operator, before giving her address.

Media playback is unsupported on your device Media caption Justine Damond's family held a silent vigil on Sydney's Freshwater Beach

"I think she just yelled out 'help', but it's difficult, the sound has been going on for a while," she continued.

Ms Damond called back eight minutes later to ensure police had the correct address.

Hennepin County Attorney Mike Freeman has said he will decide whether to charge the police officer.