A police officer in Oklahoma shot two children and a robbery suspect Friday, leaving all of them wounded, state investigators said.

Brook Arbeitman, a spokeswoman for the Oklahoma State Bureau of Investigation, said gunfire broke out when detectives with the Hugo Police Department in southeastern Oklahoma were trying to make contact with the suspect, 21-year-old William Devaughn Smith. Arbeitman said Smith is suspected in an April 11 armed robbery at a Pizza Hut in Hugo, which is near the Texas state line.

It was not immediately clear why the children were at the scene. Officials did not immediately release their names, ages or conditions.

Arbeitman said the children and Smith were taken to a hospital. Smith was treated and released at a hospital in Paris, Texas, about 30 miles (48 kilometers) south of Hugo.

Paris Police Chief Bob Hundle said he did not know the details of what happened in Hugo but that his officers took Smith into custody so that he could be booked at the Lamar County, Texas, jail on a warrant for aggravated robbery.

What prompted the shooting is unclear, Arbeitman said. She said investigators weren't sure if Smith fired at police.

Calls to Hugo police were not answered Friday evening. An employee at the city's dispatch center, who declined to give her name, said all questions should be directed to state investigators.

A post on the Huge police Facebook page says that on the day of the Pizza Hut robbery, a man entered the back entrance of the restaurant, pressed an object to the back of an employee and demanded money. Police said the worker handed over money and that the robber then left.