An 18-year-old gunman shot three people to death and wounded six others, including two police officers, in a northwest New Mexico town on Monday before police shot him dead outside a church a short time later, police said.

The late-morning shooting spree unfolded in a residential area of Farmington, New Mexico, about 180 miles (290 km) northwest of Albuquerque.

Police responded "to find a chaotic scene where a male subject was actively firing upon individuals in that neighborhood," Baric Crum, deputy chief of operations for the Farmington Police Department, said in a news briefing hours later.

Three civilians were killed, and six other people were wounded, including two officers struck in an exchange of gunfire with the suspect before he was fatally shot by police, according to Farmington police spokesperson Shanice Gonzales.

She told Reuters by telephone that the suspect had stalked about a quarter of a mile on foot firing on bystanders seemingly at random before the rampage came to an end outside the church where he was confronted by law enforcement.

No motive was readily apparent.

"We are still trying to determine why he was in this neighborhood," Crum told reporters.

The gunman, identified only as an 18-year-old, was believed to have acted alone, police said. No information was provided about any of the dead.

Some of the incident was captured in video footage posted to the social media platform TikTok and confirmed as authentic by Gonzales.

It shows a man dressed in black pacing around a driveway outside the First Church of Christ Scientist, carrying what appears to be a handgun, before he is later seen being shot dead by police in front of the building.

The man who apparently was recording the video is heard describing the scene to someone else and referring to the suspect walking in circles beside the church. He then says, "There's a person laying the middle of the street."

The two wounded officers, one from the Farmington Police Department and one from New Mexico State Police, were listed in stable condition at San Juan Regional Medical Center, according to police. The conditions of the four wounded civilians was not known.

The gun violence prompted security lockdowns at several public schools in Farmington, a city of about 46,000 residents, until police determined there was no longer a threat to the public.

Farmington, a commercial hub for oil and gas drilling and a shopping destination for the nearby Navajo Nation and smaller towns in the Four Corners region where the states of New Mexico, Arizona, Colorado and Utah meet, has experienced at least two other high-profile incidents of deadly gun violence in recent years.

"This serves as yet another reminder of how gun violence destroys lives in our state and our country every single day," New Mexico Governor Michelle Lujan Grisham said in a statement.

Police in Farmington last month killed an armed homeowner at his own house, then exchanged gunfire with his wife, after officers showed up at the wrong address in response to a domestic violence call.

Farmington also was the scene of a deadly high school shooting in December 2017 in which a gunman killed two students before taking his own life.

Monday's carnage was among the latest of at least 225 mass shootings recorded in the U.S. this year, according to the nonprofit group Gun Violence Archive. The group defines a mass shooting as any in which four or more people are wounded or killed, not including the shooter.