CLARKSBURG, Md. (AP) — Police say a student had brought a gun and a knife to his Maryland high school in a Washington, D.C. suburb.

Montgomery County police say in a statement that 18-year-old Alwin Chen was arrested Thursday afternoon after Clarksburg High School officials found he had a loaded 9 mm handgun and a knife. Police say the gun was in Chen's book bag while the knife was in his shirt pocket.

Police say Chen was escorted from class to the school office after the resource officer had received information that Chen might have brought a gun. Police say Chen's motive and how he got the gun remain under investigation.

Chen was charged with several offenses including possession of a firearm on school property. It is unclear if he has a lawyer.