A gunman shot and killed eight people and wounded at least seven others at a busy mall north of Dallas on Saturday, police said.

The gunman, whom authorities said they believe acted alone, was killed by a police officer after he began firing outside of the Allen Premium Outlets mall in Allen, Texas, the city's police chief Brian Harvey said at a press conference.

Allen fire department chief Jon Boyd said that his department took at least nine victims with gunshot wounds to area hospitals, two of whom died.

Medical City Healthcare, which runs 16 hospitals in the area, said in a statement that its trauma centers were treating eight of the wounded victims, who ranged in age from 5 to 61. The hospital did not say what condition they were in.

One unidentified eyewitness told local ABC affiliate WFAA TV that the gunman was "walking down the sidewalk just shooting his gun outside" and that "he was just shooting his gun everywhere for the most part."

The shooting was the latest episode of gun violence to strike the country. It sent hundreds of shoppers fleeing in panic.

The White House said President Joe Biden had been briefed on the shooting and that the administration had offered support to local officials.

Texas Governor Greg Abbott, calling the shooting an "unspeakable tragedy," said in a statement that the state was prepared to offer any assistance local authorities may need.

Allen, Texas, is a community of about 100,000 people.

Mass shootings have become commonplace in the United States, with at least 198 so far in 2023, the most at this point in the year since at least 2016, according to the Gun Violence Archive.

The nonprofit group defines a mass shooting as any in which four or more people are wounded or killed, not including the shooter.

(With input from agencies)