Kevin Norton, 18, and James Stumbo, 27, both of Iowa, were arrested on Saturday and charged with unlawful possession of a firearm, unlawful possession of ammunition and other firearm related charges, according to a Boston Police Department news release.
No nexus to terrorism has been revealed, but the investigation is ongoing, Officer Rachel McGuire of Boston Police Department said.
"The BPD detectives did a great job in the stop and prevention of a potential tragedy," said Superintendent Paul Fitzgerald, Bureau of Intelligence and Analysis commander.
On Thursday, authorities of the Boston Regional Intelligence Center were informed of threats made over social media to the participants of the Pokemon event being held at the Hynes Convention Center
Norton and Stumbo were stopped trying to enter the event on Thursday, Boston police said. According to its website, the players attending the invitation-only event vied for $500,000 in scholarship awards, with the overall winner taking a $10,000 scholarship.
Norton and Stumbo were detained and escorted off the premises.
Informed that the suspects drove from Iowa and were in possession of firearms, detectives asked the pair to provide license to carry. The duo did not.
They were released but their vehicle was seized, police said.
On Friday, detectives executed a warrant on the vehicle and found one 12-gauge Remington shotgun, one DPMS Model AR-15 rifle, several hundred rounds of ammunition and a hunting knife.
Police arrested the individuals at a Saugus, Massachusetts, hotel early Saturday. They were expected to be arraigned Monday.
The threats on social media were flagged by private sector public safety personnel at the convention center.
"This incident is a good example of private security reaching out to their local Boston police district and relaying information to detectives ... to identify the very real threat," Fitzgerald said.
The Massachusetts Convention Center Authority, which oversees operations at the Hynes Center -- released the following statement:
"The safety of all those that enter our venues remains of paramount importance to the MCCA. As soon as we were made aware of a potential security issue at an event taking place at the Hynes this weekend, we worked closely with the Boston Police Department and the event to take immediate steps to resolve the issue.
"The event was not directly impacted and we do not believe there is any further threat at this time."
CNN affiliate WHDH
got the following statement from Pokémon Company International:
"Prior to the event this weekend, our community of players made us aware of a security issue. We gathered information and gave it as soon as possible to the authorities [at Hynes] ... who acted swiftly and spearheaded communication with the Boston Police Department. Due to quick action, the potential threat was resolved."