Just south of the minefields, fences and watchposts of the world's last Cold War frontier, a monk pours rice wine on the grave of an unknown North Korean soldier killed 60 years ago.

The monk, 57 year-old Mukgai, is alone in tending to the spirits of "enemy" combatants -- North Korean and Chinese troops -- who died in the slaughter of the 1950-53 Korean War and whose remains lie buried in an isolated South Korean cemetery.

Every day, he performs the same Buddhist ritual, chanting sutras, banging a drum and pouring the wine in an effort, he says, to soothe the souls of young men permanently exiled in death.

Some 735 North Koreans and 369 Chinese are buried in the cemetery -- the only one of its kind in South Korea -- located a short walk from the Imjin River that forms part of the border separating the two Koreas.

Mukgai decided to devote himself to tending the graveyard after what he describes as a vivid and disturbing supernatural encounter one night in October 2011 in the grounds of the nearby temple where he lived at the time.

"All of a sudden the temple grounds were packed with the ghosts of all these dead soldiers, making a huge commotion, some of them speaking in Chinese," he recalled.

They were wearing worn-out or bloodied military uniforms, some of them complaining they were cold and hungry, begging for help and crying that they missed their homes, the monk told AFP.

"It was an unbelievable and unforgettable scene," he said.

Both moved and frightened by the experience, Mukgai said he initially tried to ignore the pleas, but was worn down by what became nightly visitations in the temple grounds.

When the temple closed, after the land it was on was sold, the monk moved to an adjacent log house and eventually embarked on his mission to bring some comfort to the soldiers' spirits.

Casualty figures from the Korean War remain disputed, but around 200,000 North Korean troops are believed to have been killed. China entered the war in October 1950 and lost around 135,000 soldiers in the fighting.

July 27 will mark the 60th anniversary of the armistice that ended the conflict but left both sides still technically at war because it was never formalised by a peace treaty.

Beijing and Pyongyang established diplomatic relations in 1992 and China is now South Korea's largest trade partner.

Relations between North and South Korea on the other hand remain extremely volatile, as witnessed most recently by a surge in military tensions in March and April.

The cemetery was established in 1996 as a final resting place for the remains of North Korean and Chinese soldiers that had been buried in small plots scattered around the country.

Initially the graves were marked with a simple wooden stake. While some carried a name, most were anonymous and identified only by nationality.

The site was poorly tended and soon fell into disrepair.

"When I first saw it, it was completely run down, teeming with rats, overgrown...." Mukgai said.

In line with Buddhist tradition, Mukgai staged a 108-day period of prayer at the cemetery aimed at releasing the souls of the dead soldiers from their torment.

His actions were criticised in some conservative circles, with questions raised over the monk's "patriotism" and suggestions that he was somehow lending comfort to the enemy.

"I don't understand why we should even bother to excavate the remains of North Korean soldiers and manage their graves," said Kim Jyung-Chan, a Korean War veterans group activist.

It's not an argument that particularly bothers Mukgai.

"Many innocent young people died in our country, but for 60 years their bodies and spirits have been trapped here by politics.

"We must warmly embrace them regardless of their nationality and console their souls," he said.

Complicating the issue slightly is the fact that not all the remains in the graveyard date back to the Korean War.

The bodies of more than two dozen North Korean commandos killed in a daring but unsuccessful 1968 attack on the presidential Blue House in Seoul are also buried there, along with a North Korean agent responsible for the 1987 bombing of a South Korean airliner that killed 115 people.

Until now, neither North Korea nor China has made any real effort to have any of the remains repatriated, despite sporadic talks between Pyongyang and Seoul on the issue of reclaiming their war dead.

Following a series of news reports about the poor state of the cemetery, the South Korean Defence Ministry -- possibly mindful of Chinese visitors -- gave the site a 500 million won ($450,000) facelift last year.

The wooden grave markers were replaced with small marble headstones, a proper road was built to the site, and staircases set up between the different terraces holding the graves.

Military guards said around 100 people come to the cemetery every month, including a steady stream of Chinese visitors, many of them from families who lost a relative during the war.

"My own hope is that it will become a place to promote reconciliation," Mukgai said. "The two Koreas should hold a joint memorial service here, apologise and promise not to fight again."