For the second time in a week, a Columbia High School student was arrested after administrators found a loaded gun on campus.

The gun was one of two discovered at DeKalb County high schools Wednesday, a district spokesman said.

The one at Columbia was found during a “search and safety drill” conducted by DeKalb County School District police, authorities said. The unannounced drills are conducted occasionally, according to the school system.

“School officials reacted quickly to apprehend the weapon as well as the student involved,” the district said in a statement. “At no time was the weapon used to threaten students or staff.”

A second gun was discovered at Cedar Grove High School, authorities said.

An employee was putting something into a student’s backpack when they noticed what appeared to be a weapon, district officials said.

School officials seized the gun and discovered it was not loaded. Both investigations are ongoing.

Wednesday’s incidents mark the fourth and fifth times guns were recovered on a DeKalb high school campus since the semester started last month.

Last Thursday, two Columbia students were arrested after administrators discovered one of them had a loaded handgun on campus.

RELATED: 2 students charged after loaded gun found at DeKalb high school

In August, Stephenson High was placed on lockdown after a student told administrators she saw someone with a gun. Police recovered the weapon and a 14-year-old was charged, district officials said.

MORE: Gun report puts DeKalb high school on lockdown; teen arrested

And earlier this month, Lithonia High was also placed on lockdown after one student pulled a gun on another.

ALSO: Student in custody after pulling gun on another student at Lithonia High

In a statement Wednesday, district officials said students caught with weapons at school can be disciplined and criminally charged. The teens arrested at Columbia and Cedar Grove are being charged with possession of a weapon on school grounds.