Officials say that more than 1,000 unexploded bombs left over from the war still litter the site.
Bomb disposal experts destroyed 130 cluster bombs and a grenade in Vietnam’s central province of Quang Ngai on Saturday, but said hundreds still remain hidden in the former battlefield.
The bombs were found on the slopes of a mountain and were detonated in controlled explosions after the area had been evacuated.
Officials said more than 1,000 unexploded cluster bombs remain on the 30-hectare mountainside.
The area is officially off-limits to the public, but many people make a living from mining and farming on the mountain, regardless of the dangers.
Explosions have occurred in the area, officials said, but without specifying casualties.
They said that clearance efforts will continue.
Bombs left over from the war are a constant threat in central Vietnam.
Unexploded ordnance still covers a fifth of the country and explosions occur frequently, killing more than 1,500 people every year and maiming and injuring 2,200 more, according to official data.