Port Authority Police officers arrested a runaway teenager from Virginia after finding him with a loaded gun at a Manhattan bus station on Friday.

Officers at the Port Authority Bus Terminal detained the 13-year-old boy about 5:30 p.m. He was armed with a loaded Glock .40-caliber handgun and 79 rounds of ammunition, Port Authority Police said.

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Port Authority officers from the Youth Services Unit learned the boy had left Wythe County and was heading to New York City with the gun on a Greyhound bus, agency spokesman Joseph Pentangelo said.

Port Authority Sgt. Hector Martinez and Lt. Jason Bailey flagged all incoming buses from Virginia to be checked by security at the lower level bus terminal with a description of the 5-foot, 100-pound boy.

Officer Len Guzman spotted the boy leaving a bus and alerted plainclothes officers to detain him. The boy told officers he wanted the gun for protection and told them, “The gun is in my bag,” police said.

Police booked the unidentified boy at the Horizons Juvenile Detention Facility in the Bronx.