Missouri police are in a standoff with a shooter who has taken hostages in a parking garage in St Charles near City Hall.
Gunfire erupted in the first floor of the garage after yelling was heard on Monday, according to St. Charles Mayor Dan Borgmeyer.
A mental health professional is on the scene as the situation unfolds, according to local media.
No injuries have been reported.
A large police presence remains by the parking garage, which serves City Hall.
Officers have closed off traffic in the area as the investigation unfolds.
Missouri police are in a standoff with a shooter who has taken hostages in the parking garage in St Charles near City Hall