Five people including a police officer and a gunman have died in a shooting at a petrol station in the United States state of Missouri after the attacker went inside and opened fire, police said on Monday.

Police said the man was also found dead, seemingly due to a self-inflicted gunshot.

The dead included three citizens, Police Chief Paul Williams announced on Monday. A police officer was injured along with another citizen.

Williams said police received reports of “multiple shooting calls throughout the city” late on Sunday.

As officers responded, witnesses reported a vehicle crashed into a Kum & Go petrol station and convenience store, and the armed attacker ran inside and began shooting at customers and employees, Williams said.