Two different students at two different Maryland high schools were found to be in possession of weapons on school grounds.

One student, who has been identified as 18-year-old Alwin Chen, was found with a handgun on Thursday afternoon at Clarksburg High School, according to a letter sent by Principal Edward Owusu.

Montgomery County police said in a report on Thursday night the gun was a loaded, 9mm handgun.

Owusu said that the school received a report shortly before 2 p.m. on Thursday that a Clarksburg student may be in possession of a weapon. After locating the student, Chen, the School Resource Officer (SRO) asked Chen if he possessed any weapons. Chen said he had a handgun in his bag and a knife in his front shirt pocket. Both were searched and the weapons were confiscated.

Chen was placed under arrest by the SRO. He was then transported to the Central Processing Unit and charged with possession of a handgun, possession of a firearm by a person under 21 years old, and possession of a firearm on school property.

He is being held without bond pending his bond review hearing on Tuesday at 1 p.m. in District Court in Rockville.

Captain Paul Starks of Montgomery County Police said on Thursday that they cannot yet give a reason why the Chen had a gun.

Alwin Chen, 18.

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“This illegal and dangerous behavior will not be tolerated in our school community,” Owusu said in his letter. “Any student caught with a weapon will be referred to law enforcement and punished accordingly.”

Principal Owusu's full letter is here.

According to AP, Loch Raven High School in Baltimore County was also placed on lockdown on Thursday after a 14-year-old student arrived with a weapon in his backpack that turned out to be a pellet gun.

In this case, Police recovered the pellet gun on the school's campus. Charges are pending.

In a series of Thursday tweets, police said the school resource officer was informed that a student was concealing a weapon. The student ran off when the officer approached. The lockdown began when the officer lost sight of the student.

Both incidents come just a day after a school shooting in Florida claimed the lives of 17 people.