Probe into 'Christchurch 2.0' online threat to mosque

A profoundly concerning online threat against a recently opened mosque has sparked a major police investigation.

A comment on the place of worship's Instagram page threatened to "Christchurch 2.0" a mosque in western Sydney, alluding to the New Zealand city where an Australian man killed 51 worshippers in a 2019 terror attack, Australian Islamic House said in a statement on Tuesday.

Places of worship need to be safeguarded from hatred and violence, the institution's president Mazhar Hadid said.

"We are profoundly concerned by this threat and take it with the utmost seriousness," he said.

"We also urge the public to remain vigilant and to stand united against Islamophobia and all forms of bigotry."

The mosque officially opened at Edmondson Park in southwest Sydney on Friday, the first day of Ramadan.

Prime Minister Anthony Albanese said whoever was responsible for the abhorrent threat should face the full force of the law.

"There is no place for this in Australia ... racism and Islamophobia will not be tolerated," he said in a statement.

NSW Premier Chris Minns said the threat is being taken very seriously and a major police investigation was under way.

"Racist threats and Islamophobia will not be tolerated and will be met with the full force of the law," he said in a statement.

"This is very distressing, particularly as Muslims right across the state are participating in prayer during the month of Ramadan."

NSW Multiculturalism Minister Steve Kamper described the threat as heinous.

"Acts designed to intimidate and divide have no place in our society," he said.

"Importantly, places of worship should always be a safe haven for our community."

Australian Islamic House said nightly prayers would continue after it had been assured of an increased police presence.

NSW Jewish Board of Deputies president David Ossip said the community unequivocally condemned the threat.

"A bigoted attack or threat targeted at any group of Australians is an attack on us all," he said.

"No Australian should have to fear for their safety when attending their place of worship."

NSW Police said in a statement initial inquiries had revealed the threat came from interstate.