SYDNEY — Authorities in Sydney are investigating whether explosives discovered in a caravan were intended for an antisemitic attack.

The explosives could have caused a 40-meter-wide blast and "significant damage," police said on Wednesday, adding that the threat was contained.

A note was found in the caravan that displayed antisemitic messages, investigators said.

"This is the discovery of a potential mass casualty event," New South Wales Premier Chris Minns said.

New South Wales Police Deputy Commissioner David Hudson told a news conference that the caravan was discovered on 19 January in Dural, a suburb of north-west Sydney.

The investigation became public on Wednesday after details of it were leaked to the media.

There was "some indication that the explosives might be used in some form of antisemitic attack," Hudson said, but he wouldn't be drawn on the possible target.

He said officers had "mitigated the risk as much as possible" but stressed: "I'm not saying it's been eliminated. I'm saying it's been mitigated."

"That's one of the reasons we're talking today, for members of the public to be vigilant in relation to what they see and what they hear in relation to antisemitism in our community."

An investigation involving the Australian Federal Police (AFP) has been launched.

Prime Minister Anthony Albanese posted a statement on X saying that "hate and extremism have no place in Australian society".

He said that New South Wales Police had "people in custody" and was working with the AFP taskforce investigating antisemitic crimes called Special Operation Avalite.

Premier Chris Minns described the incident as "terrorism".

"This would strike terror into the community, particularly the Jewish community, and it must be met with the full resources of the government."

It has not yet been designated a terrorist incident, the premier confirmed.

The discovery follows a spate of antisemitic attacks in Australia in recent months.

In December, worshippers were forced to flee as Melbourne's Adass Israel synagogue was set on fire.

Earlier this month, a childcare centre in Sydney was set alight and sprayed with antisemitic graffiti. — BBC