The start of an inquest into the Sydney cafe siege has heard that hostage Katrina Dawson was killed by fragments from a police bullet or bullets.

The inquest heard that another hostage, Tori Johnson, was killed by a bullet to the head from gunman Man Haron Monis.

That sparked the police raid on the Lindt Chocolat Cafe last month in which Ms Dawson and Monis died.

The inquest is seeking to establish exactly how the three died and whether their deaths could have been avoided.

Monis took 18 people hostage at the cafe in Martin Place in central Sydney on 16 December, holding them for more than 17 hours.

It led to a shutdown of a large part of the city centre and the biggest anti-terrorism operation in Australia's history.

Jeremy Gormly, a lawyer assisting the coroner, told the inquest that Ms Dawson was "struck by six fragments of a police bullet or bullets which ricocheted from hard surfaces into her body".

"I will not detail the damage done to Ms Dawson other than to say that one fragment struck a major blood vessel. She lost consciousness quickly and died shortly afterwards."

The inquest has now adjourned, with no date yet announced for the next hearing.

Australia media reports earlier this month had indicated that Ms Dawson, a 38-year-old barrister and mother of three young children, had died after fragments from a police bullet hit her in the heart and shoulder.

Monis, a refugee from Iran, was facing a range of criminal charges and had a history of religious activism.

He claimed to be a cleric and asked his hostages to display an Islamic flag during the siege. However, police believe he was not linked to international militant networks.

Source: BBC