After an hour of combing a grassy hill, Du Zhanlong burst into nervous laughters as his metal detector began beeping loudly, suggesting a large metal item buried beneath.
After cordoning off the site with little red flags and painstakingly removing the soil on the surface, Du and other soldiers revealed the true identity of the mysterious object -- a landmine.
A loud bang and a plume of black fume marked the demise of the decade-old bomb hours later. It was their first trophy on the 17th day of China's ongoing demining mission along the Sino-Vietnamese border.
"It's a battlefield in a peaceful time," said the 36-year-old soldier, whose regiment of around 100 soldiers is working through a minefield near the Friendship Pass, a busy border pass in Guangxi Zhuang Autonomous Region.
On Nov. 3, China launched a landmine-sweeping mission along its border with Vietnam. More than 500 soldiers from the People's Liberation Army (PLA) have participated in the two-part mission in southwest China's Yunnan Province and the southern region of Guangxi.
It was China's third large-scale landmine-sweeping mission along the Vietnam border since the 1990s. The first two campaigns were conducted from 1992 to 1994 and 1997 to 1999. From 2001 to 2008, Chinese soldiers also cleared mines for a boundary demarcation project.
Authorities have said the mission aims to secure the safety of residents and traveling businessmen in the border areas, where the booming cross-border trade has replaced turmoil.
MORE COMPLEX AND DANGEROUS
An unknown number of mines were laid along the border during confrontations between the two countries in the 1980s. Hundreds of thousands were unplugged in China's previous missions, but many are hiding.
The mines have caused serious civilian casualties over the decades and are posing greater threats in recent years, as the border region's economic take-off has increased human activity.
Du recalled in 2001, he witnessed a mine blow up a truck carrying lumber, injuring the driver. The explosive remained buried in a mountain in Ningming County until a downpour washed it onto the road.
The first landmine he cleared was buried inside a village, Du said.
Officials say the mines targeted in this round are "hard nuts" left by previous missions. Many are hidden deep in the mountains, forests or other complex terrain that makes mine-sweeping more dangerous.
A lack of official records adds to the difficulties. Of the 53 sites to be cleared in Guangxi, 13 have no record and were accidentally discovered by farmers and soldiers, said Zhu Zhanpeng, an officer with the PLA Guangxi Regional Military Area Command.
Zhu said they have employed de-mining robots, but only on flat and scarcely-wooded terrain. Most of the time, it is still soldiers who explore the rugged and densely-forested minefields in the mountainous region.
Soldiers only work in the morning, which are the "most vigilant hours of the day," as searching requires high focus, so soldiers should avoid the dozy afternoon, according to Zhu.
REMOVING HURDLES FOR TRADE
Officers overseeing the mine-sweeping mission say the removal of the dangerous historical legacy is meant to secure locals' safety, boost border trade and facilitate the areas' future opening-up.
Closer economic ties between China and Vietnam have brought unprecedented vitality to border regions once torn by conflicts. The two countries recorded 64.1 billion U.S. dollars in trade volume in the first nine months of 2015, marking a yearly rise of 12 percent.
In Pingxiang City, which administers the Friendship Pass, the booming border trade has also ignited a construction fever. The minefield Du is clearing will be used to expand a highway to accommodate the surging traffic volume through the pass, said Sun Ruijun, mayor of Pingxiang.
The city is cooperating with a Vietnamese city to build a "cross-border economic cooperation zone." Clearing the minefields will thus provide land resources for future logistic and infrastructure projects, according to Sun.
"The mine sweeping will bring faster changes to this place," said Du as he came down from the mountain after finishing the day's mission. His voice drowned out by the noise of passing trucks on a nearby road.
