At least four people were wounded on Wednesday when a gunman opened fire at a school in the southern US state of Texas, the local police department said. Three of the injured were taken to a nearby medical facility, while one refused hospital care, Jim Ross, the mayor of the city of Arlington, told the press. Authorities have started a manhunt for the 18-year-old suspect believed to be the culprit, according to a police tweet. Arlington police have identified the suspect as a student, 18-year-old Timothy George Simpkins, and are asking for the public"s help in finding him. "Please call 911 if you know the whereabouts of 18-year old Timothy George Simpkins who may be driving a 2018 Silver Dodge Charger with license plate PFY-6260," the police department tweeted. Simpkins should be considered armed and dangerous, Mansfield Police Chief Tracy Aaron said. The police department shared the suspect"s photo. Police said that they believe the suspect in Wednesday’s shooting at Timberview High School in Arlington, Texas, had fled the premises. Timberview High School is located in Arlington, Texas, near Dallas and Fort Worth. Two police officers from the Mansfield Independent School District were in the school and rendered aid immediately after the shooting, Arlington Police Department Assistant Police Chief Kevin Kolbye said. It’s unclear how the gun made it into the school. Kolbye said he believed three of those injured during today’s shooting were students and one was a person who may be a teacher, but he could not confirm those details during a news conference. He did say a pregnant woman fell during the shooting and was treated at the scene but was not transported to the hospital. Police are asking for anyone with video of today’s shooting to contact police to share the information they have. The weapon used by the suspected shooter in a Texas high school will be tracked down, pledged Jeff Boshek, the special agent in charge for the Bureau of Alcohol, Tobacco, Firearms and Explosives" Dallas Field Division. "We"ll figure out where this individual got this gun from. Our agents won"t sleep, working with our partners here, to figure out how he got this weapon in his hand to come in this school and cause this tragedy today. “So, I don"t have much information I can give you on the weapon. Obviously, we don"t have that yet. We haven"t been in the school to figure out the caliber of the weapon or anything like that yet, but as soon as we do, we"ll have something to get out to you guys," Boshek told reporters. Kolbye said that police believe the shooting happened during a "fight between a student and another individual in a class" at Timberview High School. — CNN & agencies