Four people have been arrested and more than a dozen weapons and hundreds of rounds of ammunition have been seized at a downtown Denver hotel that is close to several events planned in conjunction with the upcoming Major League Baseball All-Star Game.
Officers responding to a tip searched two rooms at the Maven Hotel, a block from Coors Field, on Friday night.
Three men and a woman in their 40s were arrested, and two vehicles were impounded to be searched for evidence.
The recovered weapons included several rifles, a law enforcement official told The Associated Press.
So far, investigators have not found any evidence to suggest the group was plotting a mass shooting or other similar attack, the official said, while cautioning that the investigation is still in its early stages.
The official could not discuss the matter publicly and spoke to the AP on condition of anonymity.
Authorities were called after an employee found the guns in a hotel room, the official said.
The men who were arrested are being investigated for possession of a weapon by a previous offender, and the woman, who has a separate warrant, is being investigated on a drug charge.
"We have no reason to believe this incident was connected to terrorism or a threat directed at the All-Star Game," the FBI said in a statement.
"We are not aware of any threat to the All-Star Game events, venues, players or the community at this time."
Denver police said in a statement the tip that led to the arrests was an excellent example of the community's "critical role" in public safety.
Coors Field will host the All-Star Game on Tuesday, but festivities have been underway in and around the ballpark and downtown for the past several days.