Photo:VCG

Two men and a woman were fatally shot, including the suspected gunman, on Monday morning outside a Walmart store in Duncan, midwestern US state of Oklahoma, local police confirmed.

Duncan Police Department confirmed in its Facebook post that a shooting happened in Walmart parking lot and one female and one male were deceased in the car and another male found dead outside the car. "A handgun was found on scene," the posted message said.

The shooting happened before 10:00 a.m. local time at parking area of the 24-hour Walmart supercenter in Duncan, about 130 km southwest of Oklahoma City, the capital city of Oklahoma.

According to Walmart spokeswoman LeMia Jenkins, no staff members were involved in the shooting and the store was not evacuated.

Duncan is a city and county seat of Stephens County and the population was over 23,000 at the 2010 census.