Chinese People's Liberation Army (PLA) soldiers using flame-throwers to detonate mines laid by China during the country's conflict with Vietnam in the 1980s, in Wenshan, Yunnan province, this week. China started a mission in the province on the border with Vietnam on Tuesday, China Daily reported. Some 400 PLA soldiers have been tasked to remove more than 470,000 mines in the area before the end of 2017. They will comb 51 mine fields in six counties along the border, an area that is home to more than 50,000 people. The mines remain buried in the mountains and dense forests despite two previous undertakings in the 1990s to remove them.