According to the sources, Prime Minister Scott Morrison said, the gunman who killed numerous worshippers in a New Zealand mosque on Friday was a right-wing extremist with Australian citizenship.
Prime Minister Scott Morrison has ordered all Australian flags on official buildings in Australia to fly at half-mast out of respect for those killed in the Christchurch terrorist attack.
A man who claimed responsibility for the shootings said in a manifesto that he was a 28-year-old white Australian who came to New Zealand only to plan and train for the attack.
Morrison said Australians were shocked, appalled and outraged by the attack. He described the gunman as "an extremist, right-wing, violent terrorist."
New Zealand police said they had arrested four people. Morrison on Friday confirmed one of those who were arrested was an Australian-born citizen. He said Australian authorities were assisting with the investigation.
A number of car bombs were also disengaged by military personnel after the shooting.
Asked if one of the attackers had been wearing explosives, police commissioner Mike Bush said they had "been made safe."
Police said they were still treating the event as ongoing and urged residents to stay indoors.
They have asked mosques around the country to close their doors.