A gunman opened fire on customers at a shopping mall near Portland, Oregon Tuesday, killing two people and wounding an unknown number of victims.

Police say the gunman acted alone and took his own life.

More than 100 police officers were searching the mall late Tuesday looking for more victims.

Witnesses say panicked shoppers fled the mall when the shooting started. Those who could not get outside hid in back rooms in stores at the Clackamas Town Center. Some witnesses say as many as 60 shots were fired.