The all-clear was given Thursday afternoon after a report of several suspicious packages were made, prompting an evacuation of the Pearl Street Mall and a shelter-in-place order, the Boulder Police Department said.
The department's record division received a report at 10:30 a.m. from an individual who said there were multiple explosive devices with remote control detonation in the vicinity of the Pearl Street Mall, said Dionne Waugh, a public information officer for the department.
Multiple agencies, including University of Colorado Police, Colorado State Patrol and others, responded to the scene and began evacuating a "large" number of people from the area.
People inside buildings in the area were told to remain inside while the investigation took place. Waugh said the shelter-in-place order was issued to about 18,000 households.
Police blocked off the area between 13th and 17th streets along Pearl Street to investigate and located three suspicious items -- a suitcase, a sandbag and a weight for a tent -- in the vicinity that were checked and cleared, Waugh said.
About 1 p.m. police said the area was cleared, but dogs trained in explosive detection and teams would continue searching the area out of an abundance of caution.