Police have recovered more than 230 explosives from a Norwell shed after a Hanover man admitted to stockpiling explosives there and detonating two of them alongside Route 53 in Hanover, according to a police report.

An automatic not-guilty plea was entered on behalf of Jonathan Allen, 30, during his arraignment Monday in Hingham District Court on 23 counts of possession of an explosive device and two counts of detonating an explosive, a court clerk said.

The police report did not say why Allen was allegedly stockpiling explosives.

Hanover police spoke with Allen at his home on Tower Hill Circle Friday afternoon after receiving a tip that he was responsible for the two explosions along Route 53 in March, a police report said.


Allen told police there was a homemade explosive device inside his home, and showed officers a 4½-inch-long brown tube packed with explosive powder, the report said. He told officers he had stored 50 more of the devices in a shed behind his parents’ home in Norwell, the report said.

Norwell police and a State Police bomb squad executed a search warrant on the shed and found 232 explosives, the report said.

“Due to the amount of explosives, if, God forbid, there was a fire in the shed or an explosion it could have resulted in serious injury,’’ Norwell Police Chief Theodore Ross said. “But it wasn’t a situation where we felt we had to evacuate neighbors.’’

Members of the bomb squad disassembled 20 of the devices, separating the explosive powder from the cardboard tubes, and sent the components to a lab for testing, the report said.

Hanover and Norwell police then located Allen at a Hanover home and arrested him, the report said. He was ordered held without bail at his arraignment Monday.