An incident of shooting has been reported at Great Mills High School in United States' Maryland, the CNN reported.
"The school is on lockdown," the CNN quoted the school district as saying, and the incident has been contained. "Sheriff's office is on the scene; additional information to follow."
The St. Mary's County Sheriff tweeted, "there has been an incident at Great Mills High School. Parents please DO NOT respond to the school."
Further details awaited.