KHE SANH, Vietnam — Swishing his metal detector across the red dirt of his backyard, Le Van Thang points to the spot where he buried two grenades.

He found the explosives about five years ago while plowing the family garden. He says he called authorities to take them away, but they refused. “The soldiers said two grenades weren’t enough to bother with,” Thang explains. “They said to call them back if I found more.”

The explosives have been sitting there under a tree, just a couple of yards from his back door, ever since.

Thang lives just outside Khe Sanh, in Vietnam’s Quang Tri province. His two-room concrete home sits on a jungle-covered hilltop about 15 miles from the former demilitarized zone (DMZ). Until 1975, the DMZ divided the communist north from the pro-Western south. It was the site of some of the fiercest fighting of the Vietnam War, and as a result, is littered with explosives.

Unfortunately, Thang’s situation is not uncommon. Thirty-five years after the end of the war, families across the central provinces live in fear of explosions that happen on a regular basis.

In early 2010 alone there were several blasts. Locals were burning a stump when a bomb rocked a schoolyard in Dong Ha, about 30 miles east of Khe Sanh, shaking walls and shattering windows. Luckily all 550 students were in class at the time of the blast and escaped injury.

About a week later, a man was seriously injured while weeding a coffee plantation beside the former U.S. Marine base outside Khe Sanh. Then, in February, just before the Vietnamese New Year, a 40-year-old man was killed while clearing weeds from his banana trees.

Many of the accidents involve unexploded cluster munitions, large weapons often deployed from the air that release dozens, sometimes hundreds, of smaller, baseball-sized “bomblets,” or “grenades.” They were widely used in the central provinces during the Vietnam War.

Cluster bombs blanket large swaths of land and have a high “dud” rate, meaning they don’t explode on contact and go on injuring and killing civilians long after wars officially end. Experts say the cluster bombs used in Vietnam are estimated to have a “dud” rate between 5 and 40 percent.

Three years ago, while digging for scrap metal, Thang came across a cluster bomb and carries the scars of that encounter with him today. Watch this video about Thang's experience:

Some countries are taking action to see that accidents like the one Thang experienced can be avoided in the future. The Convention on Cluster Munitions becomes binding international law Aug. 1. So far, 106 countries have signed the treaty, with Britain joining the list in May. However support has been slow to come from the world's biggest cluster bomb makers — Russia, China, Israel and the United States.

The U.S. hasn't used cluster bombs since the beginning of the Iraq War in 2003, but it has held out on signing the treaty and still has a large stockpile of the weapons. Stephen Goose, the Arms Division Director of Human Rights Watch said it’s crucial that the U.S. sign. "As one of the biggest users, producers, traders and stockpilers of cluster munitions, getting the U.S. on board is key,” Goose said. “The U.S. joining will greatly increase the international stigmatization of the weapon, and convince many of the other hold-outs to come on board.”

A 2009 study by the Vietnamese Ministry of Defense’s Technology Center for Bomb and Mine Disposal and the Vietnam Veterans of America Foundation notes that about 7,000 people have been injured or killed by explosives left from the Vietnam War era in Quang Tri Province alone.

The report also highlights a correlation between poverty and the impact of landmines and unexploded ordnance (UXO). “[The presence of UXO] creates a burden of fear and concern among people living in contaminated communities,” the report states, which hinders construction of housing, expansion of infrastructure, resettlement initiatives and other development activities.

Vietnam’s shift from a centrally planned economy to a market-driven economy in the mid-'90s raised the annual household income from $220 per year to more than $1,000 in 2009. Even during the global economic downturn, Vietnam’s economy is one of the fastest growing in Southeast Asia, at more than 5 percent. But the countryside, where Thang lives, remains mired in poverty.

Every time a new building or road is constructed or a new field is plowed, a survey has to be completed to ensure there are no explosives. That takes time and money. Surveys are currently being provided by several NGOs, but the process is slow.

NGO leaders say they are eagerly awaiting a national mine policy from the Vietnamese government, which they hope will speed things up. Critics also note that Vietnam might attract more international funding for mine removal if it signed on to the international treaties prohibiting the use of landmines and cluster munitions.

After a reporter visited Thang’s house, an NGO removed the explosives from his land — a small step toward in the daunting task of cleaning up the country. Demining efforts are underway in Vietnam, but experts say at the rate they're going, it will take at least 300 years to finish the job.