Zhang Zhongjun, a sergeant commanding a mine-detection squad near Laoshan Mountain, said the mission will be more difficult this time around because the troops will have to climb the steep mountain slopes wearing protective gear that makes it difficult to move freely.

"But we are much safer when we wear the gear. Even if a mine does explode, it will probably only cause a relatively minor injury, such as a fracture," the 22-year-old said, adding that the team faces far more pressing challenges. "Sadly, our demining robots and other high-tech equipment are virtually useless here because of all the steep slopes and dense jungle," he said.

Cheng, the lieutenant colonel, said most of the minefields in the area are inaccessible by vehicle, and after lying concealed for so long, the mines may have degraded over the years, making them doubly dangerous. They will almost certainly have shifted position too, disturbed by the heavy rains and flooding to which the area is prone.

Looking forward

The widespread distribution of land mines has been a contributory factor to the grinding poverty that afflicts many villages along the Yunnan stretch of the border, according to Hou Renxu, Party chief of Jinchang township in Maguan, a county close to Malipo.

More than 5 sq km of the land in and around Jinchang is still littered with mines, and Hou said many residents have been injured as they tried to lead their livestock out of minefields, although last year, only one resident was injured.

"Every time a villager is injured, a sense of anxiety spreads among the people. Even if we manage to clear all the mines, the trauma will live long in their lives," he said.

Wang Kaifu is mulling building a museum of mines and explosives near the Balihe village so future generations will understand the pain the older residents endured. He plans to collect mine cases, grenades and artillery shells, then repaint and exhibit them to explain how they function and how to deactivate them.

"We need to explain to future generations that the mines were everywhere here, and that they are part of the painful history of our village," he said.

Contact the writer at xuwei@chinadaily.com.cn