A federal judge in Newark on Thursday ordered alleged synagogue firebomber Nicholas Malindretos held without bail following a brief hearing.

Federal agents found gasoline, wicks and lighters in his home, as well as notes with a circle drawn in a 10-mile radius on a map, with “a ten-mile radius of targets” with police and military as potential targets, prosecutors said.

They referred to unspecified mental health issues, but U.S. Attorney Philip Sellinger declined to elaborate.

“This defendant has been charged with a very serious offense: throwing a firebomb at a facility, the temple, which has maximum of 20 years in prison,” Sellinger said.

He declined to say whether bias charges could be added but noted, “This investigation has just begun.”

Prosecutors said Malindretos, who is 26, has no prior felony arrests, has no home and has been living in a friend’s basement apartment.

“Hate crimes have got to stop, but until they do the F.B.I. and all of our partners will make it a top priority to investigate them and bring them to resolve,” said James Dennehy, special agent in charge of the FBI’s Newark office.

Malindretos is charged with attempted use of fire to damage and destroy a building used in interstate commerce.

Investigators tracked him down through surveillance video and the license plate of a vehicle he was driving.

The masked vandal was caught on surveillance video approaching Temple Ner Tamid in Bloomfield early Sunday and tossing a Molotov cocktail.

The video shows the suspect strolling around the property and appearing calm as he walks to the side of the building.

He then lights the device and throws it at the front door of the synagogue.

It didn’t cause any damage. Officials found the device and notified police.

Members of the New York and New Jersey Anti-Defamation League met Monday morning in the city to address the growing numbers of attacks in the Tri-State area on Jewish people and their houses of worship.

On Tuesday, New Jersey Governor Phil Murphy visited the temple to support the investigation and let community members know they are not alone.