There was no "credible threat" against presidential candidate Barack Obama in Denver, US Attorney Troy Eid said Tuesday. ( dpa )
Three men arrested Sunday will face drug and gun counts, but were not charged with either threatening to assassinate Obama or any other national security-related crimes, Eid said.
An unnamed female informant is believed to have contacted the US Secret Service about a threat against Obama, and indicated the involvement of the three arrested men, CNN reported quoting an affidavit from Eid's office.
"We can say this: We're absolutely confident there is no credible threat to the candidate, the Democratic National Convention, or the people of Colorado," Eid said earlier.
The case began when local police stopped a suspected drunk driver in a pickup truck in Aurora. The 28-year-old man was found in possession of methamphetamine.
Police also seized two rifles, a high-powered scope-attachment and ammunition from the vehicle.
He led them to his hotel room in Glendale, Colorado, where as police arrived a second man leapt from a sixth-storey window to an awning four floors lower, falling to the ground and suffering a leg injury.
The second suspect and a third man arrested at a Denver hotel were both held on outstanding warrants.
The Democratic Party's presidential nominating convention opened Monday evening in Denver. On Thursday, Senator Obama is scheduled to deliver an acceptance speech at a football stadium to a crowd of 76,000, becoming the first African-American to win a major-party presidential nomination.
Federal, state and local police are a strong, visible presence throughout Denver, with police dressed in riot gear on many street corners or hanging on to pickup trucks that rush to possible threat scenes.