A report of shots fired near the Colorado state Capitol briefly put the building on lockdown Thursday.

Police are still investigating what happened but said there were no reports of any injuries. A photograph from The Denver Post showed police taking a man into custody outside the Capitol.

Witnesses told Denver media outlets that two people shot at each other. A number of shell casings were seen on the street.

Joshua Crews, 36, told The Denver Post that he was waiting for a bus nearby when he heard about a dozen shots before getting on the bus. He rode the bus past the Capitol and then police stopped it soon afterward.

Dustin Cabellos told the newspaper that he was near the Capitol when he saw gunshots coming from a vehicle. He dove behind a barrier to protect himself.

“There was a lot of traffic at the time,” Cabellos said.