A man who stole a pickup truck in Paris and led police on a chase that ended Sunday night at a convenience store in downtown Mexico was found dead after exchanging gunfire with a state trooper and Mexico police officer, Maine State Police said.

The man was found dead inside the pickup truck, which was outside the Circle K convenience store on Main Street.

It was not clear if the man was killed by police bullets or killed himself, Stephen McCausland, spokesman for the Maine Department of Public Safety, said late Sunday.

McCausland said the Maine Attorney General’s Office will investigate because police officers were involved in the incident.

State law requires that all officer-involved shootings be investigated by the AG’s Office. If it is determined that the man was shot by an officer, it would be the sixth officer-involved shooting in Maine this year.

McCausland said the cause of death will be determined by the state medical examiner’s office.

The man’s identity was not being released until Monday, according to McCausland.

No police officers were injured in the incident at the gas station. It began around 7 p.m. when a “lone male” suspected of stealing the pickup truck from the town of Paris was seen at the Circle K convenience store and gas station, McCausland said.

Photographs on Twitter, the social media website, show a white pickup truck leaning against a post that is near a gas pump at the Circle K station.

McCausland said the man remained inside the pickup truck during the standoff. Officers from the state police, the Mexico and Rumford police departments, and deputies from the Oxford County Sheriff’s Office surrounded the pickup truck and closed off the downtown area to the public.

McCausland said the section of Main Street near the Circle K was expected to remain closed for several hours late Sunday and early Monday.