Two Iowa men were ordered held on $150,000 bail Tuesday on allegations that they arrived in Boston armed with an assault rifle and shotgun after making threats against a gathering of Pokémon players from around the world in August, prosecutors said.

James Stumbo and Kevin Norton pleaded not guilty in Suffolk Superior Court at their arraignment on indictments, charging them with unlawful possession of a large capacity weapon and other crimes.

The two men have been held on firearms charges since August, when authorities allege they found an AR-15 rifle, 12-gauge Remington shotgun, hundreds of rounds of ammunition, and a hunting knife in the 2002 Chevrolet Prizm the men had driven to Boston.


Prosecutors have said Norton, 18, of Ames, Iowa, and Stumbo, 27, of Boone, Iowa, had posted online messages threatening the competition at the Hynes Convention Center.

In one of those postings in a Facebook page called "Mayhem Pokemon Crew," Stumbo allegedly shared a photo of a white sedan with two long guns crossed over the trunk. "Kevin Norton and I are ready for worlds Boston here we come!!!" the post said.

Boston Police were notified of the concerning online statements and threats allegedly made against the event and an individual attendee, prosecutors said.

At a previous appearance in district court, defense lawyers for the men said there was no evidence that Stumbo and Norton planned to carry out the attacks. The charges they face are related to the guns, the lawyers said, not the threats.

Neither man is licensed to carry a firearm in Massachusetts or Iowa, prosecutors said.

Authorities say they believe the men were prepared to commit a "mass casualty situation" at the contest. Norton and Stumbo are scheduled to return to court Nov. 19.

Andy Rosen can be reached at andrew.rosen@globe.com. Follow him on Twitter @andyrosen.