Two people were killed by a gunman who was later shot dead by police in downtown Chicago, Ill. on Friday, CNN reported.

The incident took place in the Citigroup Center, a downtown skyscraper, when a gunman armed with a snub-nose revolver, knife and hammer shot four peopl, killing two.

The gunman took a hostage before being shot dead in exchange of fire with the police, according to the report.

The two injured have been sent to hospital. There is no immediate information about the hostage.

Witnesses said they heard gunshots fired on the top floor of the 38-story building.

The train station inside Citigroup Center building was temporarily closed due while the incident unfolded.

Police were still investigating the shooting and no other details were released.

Source: Xinhua