St Mary’s County sheriff’s spokeswoman Cpl Julie Yingling said there had been no fatalities at Great Mills high school.
The two victims were shot, Yingling said, but she did not know how the shooter was injured. She also did not have the identities of the any of the three injured. All three had been transported to hospitals, she said.
Last month, 17 people were killed in a shooting at a high school in Parkland, Florida. Student survivors of the assault-rifle attack have since emerged as national campaigners for gun control reform.
Saturday will see a March For Our Lives rally in Washington.
Last month, the St Mary’s County sheriff’s office said it arrested two teenage boys for “threats of mass violence” and a 39-year-old man on related charges after the teens made threats about a potential school shooting at nearby Leonardtown High.
Police said they obtained search warrants and found a cache of semi-automatic rifles, handguns and other weapons.
Great Mills high school has about 1,600 students and is near the Patuxent River Naval Air Station, about 65 miles south-east of Washington DC. St Mary’s County Public Schools first reported the shooting, saying the event was “contained” and the campus was on lockdown.
The sheriff’s office said there was an “incident” at the school and asked parents to stay away from the campus and report instead to Leonardtown High School.
The school is in the congressional district of Democratic House whip Steny Hoyer. He tweeted that he was monitoring reports and urged people to follow the instructions of local law enforcement. Maryland governor Larry Hogan also said he was monitoring the situation.
The Baltimore Sun reported that a student said the shooting happened around 8am. Terrence Rhames, 18, told the paper he heard a gunshot and saw a girl fall as he ran for an exit. “I just thank god I’m safe,” Rhames said. “I just want to know who did it and who got injured.”
FBI spokesman David Fitz said agents were on the scene to assist the sheriff’s office.
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