These M26 grenades were found within a rice cooker inside a dumpster at Wooshin High School in Seoul, South Korea, Aug. 23, 2025. (Guro Fire Station)
Three hand grenades discovered at a high school in South Korea’s capital and on a hill inside the city prompted two separate emergency responses by the South Korean army within a week, according to spokesmen from local fire stations.
A janitor at Wooshin High School, in the Guro District of western Seoul, found a pair of Korean War-era M26 grenades Saturday within a rice cooker inside a dumpster, a spokesman for the Guro Fire Station said by phone Thursday.
Army explosive ordnance disposal technicians retrieved the grenades about 90 minutes later, the spokesman said.
Police determined that a faculty member found the grenades on the campus July 29 and kept them in the rice cooker believing they were not a threat, the spokesman said.
An M26 grenade weighs 16 ounces, about a third of it in explosives, and detonates within 4 to 5 seconds after being triggered, according to a U.S. Army technical manual dated June 1966.
The South Korean army did not immediately respond to a request for comment by phone Thursday. South Korean government officials speak to the media on the customary condition of anonymity.
Following the incident, the Seoul Metropolitan Office of Education held an emergency meeting Monday to review safety protocols at its schools, according to a news release from the office the same day.
“We take this case seriously, and we will prioritize students’ right to learn and their safety,” office superintendent Jeong Geun-sik said in the release. “We will do our utmost to preemptively eliminate danger in schools and provide a safe educational environment.”
In a separate incident Wednesday 15 miles east of the school, a passerby found an unspecified grenade near Daemo Mountain, a 960-foot hill in the Gangnam District with scenic views of the capital city, according to a Gangnam Fire Station spokesman.
The person placed the grenade on a pile of stones before calling the police, said the spokesman by phone Thursday. Military explosive technicians retrieved the grenade and no injuries were reported, he said.
Unexploded ordnance dating to the 1950-53 Korean War is occasionally unearthed throughout South Korea.
A 1,000-pound AN-M65 general-purpose bomb was discovered March 7, 2024, at a construction site in Cheongju city, approximately 60 miles south of Seoul. The detonator was removed without incident, the South Korean air force said at the time.
Up to 2 million unexploded mines and ordnance remain in the Demilitarized Zone dividing the Korean Peninsula, the U.N. Command says on its website.
