Thousands of men travelled vast distances from a poor part of rural China to seek their fortunes mining gold in west Africa -- but now their dreams are in tatters with a wave of arrests and allegations of deadly violence.

Zhuo Haohe's ashes were buried in a field near his home in Shanglin county this week, after his son flew home with his remains stuffed in his luggage following a deadly attack by shotgun-wielding bandits in Ghana.

"We helped the local people get rich, and when they got rich they bought guns to rob us," said Zhang Guofeng, the dead man's brother-in-law, miming the action of firing a weapon as raindrops fell on an unpaved road.

The miners of Shanglin are an illustration of the tensions created by Chinese migration to Africa. At home popular pressure increases on Beijing to protect its citizens abroad.

With its simple white-tiled farmhouses, Shanglin county, in one of China's poorest provinces, Guangxi, seems a world away from the gleaming towers of the cities thrown up in the country's economic boom.

Its men learned mining techniques while pioneering the development of gold reserves in China's cold northeast in the 1990s.

A decade ago a few of them took their skills to Ghana, where a number made their fortunes from small-scale mines in areas ignored by Western conglomerates.

On their return to China some of the miners bought foreign cars and expensive villas and the trickle of emigres turned into a flood.

"Before we started going to Ghana, we didn't have enough money to be sure we could get a decent meal every day," said Zhang.

More than 10,000 people from Shanglin have moved to Ghana -- Africa's second-largest gold producer -- according to local government estimates.

In recent years Beijing has also poured billions in aid and investment into Africa, transforming its relationship with the continent as it seeks resources to power its own economy.

The Shanglin miners are part of a huge diaspora of small businessmen, traders and migrants who have come in the wake of the official contracts, but their presence has sometimes brought accusations of exploitation and feelings of resentment.

Ghanaian authorities say they have rounded up more than 150 Chinese illegal miners as part of a crackdown on activities they say are unauthorised and they blame for harming water supplies and the environment.

The campaign, which has also netted other foreigners, would continue until "some sanity has been restored in that sector of the economy", an immigration spokesman said.

But relatives in Shanglin say Chinese miners have been targeted in a wave of violence, and are angry that neither Ghanaian nor Chinese authorities have confirmed fatal attacks.

They say raids on Chinese mines have been carried out by men in uniforms who have been complicit in violence.

"They robbed us with double-barrelled shotguns used for hunting, but recently they have been using AK-47s," said Zeng Guangqiang, who arrived home from Ghana in May.

Returned miners deny they were operating illegally and say they had agreements with local landlords, often tribal leaders.

Thousands of Chinese have fled into hills and forests in fear of violence or arrest and deportation, Shanglin residents said. They accused Beijing of indifference as they showed to AFP images on smartphones they said were taken by relatives in Ghana and sent via online messaging services.

Some were of groups of Chinese men apparently held in detention cells, while others showed miners camping in the countryside, allegedly after fleeing.

Zhuo Shengwen, 20, the dead man's nephew, posted the photographs on Chinese social media sites, where millions forwarded them -- highlighting new pressures on Beijing's foreign policy from online activism.

"We wanted to use the internet to bring attention to our villagers," he said.

China's embassy in Accra said on its website Sunday that more than 190 Chinese citizens arrested by local authorities would be released and returned home.

But Chinese reporters have been warned not to publish their own estimates of the numbers detained, sources with knowledge of press censorship instructions who asked to remain anonymous told AFP.

"News editors received an order to report in accordance with Xinhua," one reporter said, referring to China's state-run news agency, adding: "There are a lot of details we are not allowed to report."

Ghana has a nascent oil industry and China has expressed interest in investing. In 2011, Ghana announced plans to borrow $800 million from China to build natural gas infrastructure.

On the flip-side many of the Shanglin miners now face huge losses, unable to pay heavy interest rates on private loans taken out to fund their African investments.

"People will say this will put our economy back 10 or 20 years," said Huang Liping, whose husband is among those in hiding in Ghana. "We will end up poorer than when we started.

"Everyday we hear reports that someone has been killed... it's too cruel," she said, shaking with tears and cradling her four-year-old daughter. "I feel the government is far away from us."