Two Iowa men suspected of making violent social media threats to people attending the Pokemon World Championships in Boston have been arrested on gun charges.

Boston police said Sunday that convention security reported the threats on Thursday and the suspects were stopped as they were about to enter the event hours later.

Police said they released the men, but seized their car after learning they might have guns inside.

Police said a warranted search of the car Friday found a 12-gauge shotgun, an AR-15 rifle, several hundred rounds of ammunition, and a hunting knife. Police said 18-year-old Kevin Norton, of Ames, and 27-year-old James Stumbo, of Boone, were arrested at their hotel in Saugus, north of Boston.

They are being arraigned on firearms charges Monday. It's not immediately known if they have attorneys.