UPDATE 11:40 a.m. EST:
Sheriff Tim Cameron has confirmed that the student shooter was fatally shot by the trained school resource officer, according to The Associated Press.
On Tuesday morning, authorities responded to a school shooting at Great Mills High School in Maryland.
The Associated Press has confirmed that three individuals, including the shooter, have been shot.
According to local reporter Peggy Fox, Sheriff Tim Cameron has confirmed that a shooting occurred this morning in a hallway by a Great Mills student, who was eventually engaged by an armed resource officer.
The shooter reportedly fired at a female student and another student was hit, reports Fox. An armed school resource officer then engaged the shooter with a firearm. The female student and the shooter remain in critical condition.
The St. Mary's County Public Schools, via Twitter, announced that the incident has been "contained."
Great Mills student Jonathan Freese told CNN on air that he was in lockdown in a classroom and that officers were in the school.
"I'm still a little shaken up," he told CNN via cellphone.
"I didn't really expect for this to happen. I do always feel safe, though, because they always have police at the school," he added.
"Our prayers are with students, school personnel, and first responders," wrote Maryland Governor Larry Hogan via Twitter.
Updates to follow.