Ololade Adeyanju/
Three students, including the gunman, are in critical condition following another shooting at a school in the US this morning.
The shooting happened just after classes started at Great Mills High School, Maryland around 8.15am.
Police said the shooter pulled out a gun and shot a teen boy and a teen girl before being injured himself in a shootout with a school resource officer.
The school resource officer was reportedly not injured in the shooting.
Shortly after 8.30am, the St Mary’s County Sheriff Tim Cameron confirmed there had been a shooting at the school, but said the situation was “contained”.
Parents were told to stay away from the school, and to instead go to nearby Leonardtown High School to be reunited with their children, who will be taken there once they are evacuated from their classrooms.
MailOnline reports a student named Jonathan Freese called into CNN while he was in lockdown in his math class and said that the shooting happened just after school started, in the art hallway.
“I’m still a little shaken up. I didn’t think it would happen,” Freese told CNN.
Maryland Gov. Larry Hogan said he is “closely monitoring the situation”.
“Our prayers are with students, school personnel, and first responders,” Hogan tweeted.
Reports say FBI agents are on the scene and helping local law enforcement teams investigate.
The shooting comes just four days before the March for Our Lives, a demonstration in Washington, DC and in other cities across the US, calling for increased gun control.
The march was organised by survivors of the February 14 school shooting in Parkland, Florida that left 17 dead.
That shooting has led to a renewed debate about gun control laws.
US President Donald Trump 