An office building in Dallas is safe following reports of a person with a gun, police said.
However, they have not confirmed whether any shots were fired or if anyone was injured or killed.
Police said on Twitter that the building was "made safe" at 12.49pm local time on Monday, adding that they are still in the early stages of investigations.
Television footage showed a heavy police response, including a SWAT team, at the office building near a multi-level highway interchange known as the High Five.
A broken window could be seen on one of the upper floors of the mirrored tower.
The building at 8330 LBJ Freeway has been made safe at 12:49pm.
— Dallas Police Dept (@DallasPD) April 24, 2017
Bailee Christian told KXAS-TV that she heard two gunshots - one while she was in the building and the other after her office had been evacuated.
She said: "It was very intense in the moment, very scary."
She added that one of the police officers who helped evacuate the office had a small amount of blood on his arm, appearing to have a minor injury.
Police have said one officer was injured by debris.
AP