Soldiers employ flamethrowers at the edge of a minefield to clear paths for demining operations.

In 1981, Wang Kaifu's father was killed when he stood on a concealed land mine as he patrolled Dongshan Mountain with other members of the local militia. The number of land mine-related injuries and deaths rose steadily in the 1980s, and Wang Kaifu will never forget the smell the mines emitted after they exploded. "It was the smell of TNT mixed with blood. Just a faint whiff could make you nauseous," he said.

As one of the youngest men in the village, Wang Kaifu, 36, has often been tasked with dangerous expeditions, such as entering minefields to carry injured villagers to safety. He said most of the devices near the village are antipersonnel mines, so the force of the blast can rip off a leg or cause blindness, but rarely results in death.

"Even so, that's enough to make your whole life too miserable to endure," he said, adding that several young men in the village took their own lives after being injured by land mines.

During the clearance miss-ions in the 1990s, the provincial government erected signs to alert villagers to the hidden danger, but Wang Qingming said it's impossible for the locals to avoid the minefields completely.

"We have no alternative. We need to go to the mountain for firewood and food for our livestock," he said. "For us, the supply of natural gas or liquefied natural gas only exists in our dreams."

Wang Kaifu said most of the injuries occur when villagers are fetching fodder for their pigs. "There is no other source of income, so we have to risk it," he said.

In the danger zone

The mountainous terrain and dense forest cover present harsh challenges to the members of the PLA demining teams, according to the officers.

"Nobody knows for certain where each mine was laid, or where they are right now," said Cheng Dengquan, a lieutenant colonel who commands a minesweeping unit on Laoshan Mountain, the scene of intense fighting during the border conflicts. "We can sense the eagerness of the villagers because they sent welcome messages the minute we arrived," he said.

The mines were laid by several different PLA units over a number of years, according to Cheng: "That's why the mines along the border were distributed in a very chaotic manner."

Wang Kaifu said the villagers are grateful to the soldiers, and will use their local knowledge to help them unearth the devices with as little risk as possible. "For them to conduct a mission in an area with which they are totally unfamiliar is a massive challenge in itself," he said.

The third mission is necessary because the two previous operations were unable to clear all the mines scattered across the area. When the previous missions were undertaken, the line of the border was the subject of high-level negotiations that lasted until 2009, when the issue was finally resolved.

However, many of the soldiers involved in the latest mission have accrued a huge amount of experience, either through previous operations in the area, or through miss-ions undertaken as members of UN peacekeeping forces.