Australian police say a trailer laden with explosives found on the outskirts of Sydney last week is the latest escalation in a series of antisemitic attacks in the country.

Authorities said police found a trove of the mining explosive Powergel along with a list of “Jewish targets” in the trailer, which was discovered earlier this month.

New South Wales State Deputy Police Commissioner David Hudson told reporters that the materials could have created a massive explosion.

“The use of explosives have the potential to cause a great deal of damage,” he said. “This is certainly an escalation.”

Commissioner Hudson declined to disclose the names found on the list of targets but said that those on the list will be identified. Several suspects not directly related to the trailer have been arrested, he said.

“This would strike terror into the community, particularly the Jewish community, and must be met with the full resources of the government,” New South Wales Premier Chris Minns said.

Authorities were quick to connect the trailer’s contents to the string of graffiti and arson attacks that have plagued Sydney and Melbourne’s Jewish communities. Several fire attacks on synagogues are being investigated by federal and state law enforcement under a joint counterterrorism team.

“This is the discovery of a potential mass casualty event,” Mr. Minns said. “There’s only one way of calling it out and that is terrorism. That’s what we’re very worried about.”

• Vaughn Cockayne can be reached at vcockayne@washingtontimes.com.