The grenades were among 1,414 unexploded ordnances (UXOs) found in two munition bunkers on a hill in Trieu Son Commune on Monday and Tuesday.

The munitions, produced and used by the U.S. in the Vietnam War, included grenades, mortars and motor rockets, MAG officials said.

Quang Tri, a major battlefield during the Vietnam War, was hardest hit by bombings. It was a center for American military bases and principal battleground during the 1968 Tet Offensive, as well as the location of the demilitarized zone (DMZ) that separated the North and South.

After Vietnam reunified in 1975, only three out of Quang Tri's 11,000 villages remained intact and over 390,000 hectares (964,000 acres) of land, or 82 percent of its total area, were said to have unexploded bombs and explosives.

According to the Quang Tri Military Command, there are still over 100,000 tons of unexploded ordnance (UXO) underground or underwater, including bombs, mines, missiles, rockets, artillery and mortar shells, and other explosive devices.

Unexploded ordnance still threatens a fifth of Vietnam’s land mass and explosions are not uncommon. According to the United Nations, 104,000 Vietnamese people have been killed by bombs, landmines and artillery shells since the end of the war in 1975.

Many people from poor rural areas have been killed or maimed by inadvertently triggering the devices, or while trying to cut them open to resell the explosives and the metal to scrap dealers.

The MAG, an international group specializing in detecting and handling unexploded ordnance, has been operating in Quang Tri since 1999. Last year, the group destroyed over 100,000 landmines and unexploded bombs and cleared about 55.8 million square meters of land from unexploded ordnances.