The Zimbabwe government is struggling to contain a nationwide wave of illegal prospecting for precious minerals and metals that is threatening the viability of the already troubled mining industry, on which rests the hope of turning around an ailing economy by generating foreign currency earnings.

Analysts attribute the "frightening" magnitude of illegal mining and sale of vital minerals on the unofficial market to a desperate population seeking to beat poverty, and poor government policies regulating the mining industry.

"The government has let this thing [illegal mining] go on without control for too long, and the industry is now driven by the black market," said Innocent Makwiramiti, an economist and former chief executive officer of the Zimbabwe National Chamber of Commerce (ZNCC). He told IRIN the country could have lost billions of dollars in revenue.

Manicaland Province, bordering Mozambique to the east, has gained overnight fame for the widespread panning activities of thousands of illegal miners, popularly known as 'makorokoza', who have turned vast tracts of land into open-pit mines in their bid to extract a variety of minerals, including diamonds, emeralds and gold.

The police, army, prison guards and graduates of the ruling ZANU-PF government's national youth training centres have been deployed along the roads leading to and from Mutare, the provincial capital on the Mozambique border, and the heavy security presence extends to Marange District, a large communal land area about 40km to the south and west, and even further to Buhera, a town in Marange District, about 200km southeast of the capital, Harare.

Roadblocks have been set up to stop and search private and public transport vehicles for minerals and those suspected of illegal mining activities arrested. But the clampdown has had little effect on the activities of the miners or the precious metal and gem dealers drawn to the area.

"We have become cautious after the police descended on Buhera in December [2006], but business continues as usual," Samson Munhangu, 21, an illegal miner, told IRIN.

Munhangu, from Chivu, about 140km south of Harare, in Mashonaland East Province, operates in the Jori area of Manicaland, which the diggers and panners have reduced to rows of gullies in search of emeralds. He is one of more than 3,000 illegal miners in Buhera constantly on the lookout for the patrolling security details that are trying to stop the illegal mining.

"I am more afraid of the soldiers and the Border Gezi [youth training graduates], who can beat you to death if they decided not to have you arrested," said Munhangu. He spent two nights hiding in a mine pit when the Jori area was raided by government security forces.

To avoid detection, Munhangu, like others operating in Buhera, is no longer selling the emeralds near the mining works, but routinely travels to Mutare's poor suburb of Sakubva to meet buyers from Harare, and foreign dealers from the neighbouring countries of Mozambique, Botswana and South Africa.

Sometimes he has travelled through the night on foot to beat the roadblocks on the way to Mutare, a journey of about 60km. The foreign dealers usually paid him in foreign currency for the emeralds or with cell phones, second-hand clothes and electronic goods, while dealers from Harare paid in Zimbabwean currency.

Some panners were even grinding bottles to take advantage of the mining hysteria sweeping across the region, and passing them off to dealers as emeralds. "With the way the economy is going, you have to do everything you can to make money while you can," said Munhangu.

For the past eight years Zimbabwe's economy has been in meltdown, characterised by a slew of shortages, including foreign exchange, food, clean water, fuel and energy. The industrial base has shrunk by more than a third, unemployment levels are touching 80 percent, and inflation has reached 1,281 percent - the highest in the world - putting most commodities, when available, beyond the reach of most people.

Instant riches from the sale of the minerals has transformed the lives of many people in Marange District in central Manicaland Province, where police estimated that around 15,000 illegal diamond panners had descended before they sealed off an area known as Chiadzwa.

Clephas Mharidzo, a village headman in Marange District, said he was "amazed" by the changed lifestyles of some of the local villagers since they began prospecting for diamonds in Chiadzwa.

"That should be the work of our gods. Many of our sons and daughters have managed to build the types of houses that can only be afforded by people living in the cities. Some of them have even bought cars, even though they cannot drive," Mharidzo told IRIN.

In March 2006, the headman said, the ancestral spirits of the area ordered that the people of Marange should be left to pan for the diamonds in an area that used to belong to a German mining company.

"The spirits had the noble idea of empowering the local community, but things started going wrong when makorokoza from all over the country invaded Marange and turned it into a wasteland. Even the government had initially agreed that we pan for diamonds, but when the greedy ones came the politicians changed their minds," he commented.

Although the security forces were carrying out patrols, Mharidzo said a significant number of his subjects still had diamonds hidden in their houses, and the mining fever was making children abscond from school to dig for the precious stones.

"Whenever you have a good thing, bad things follow. Prostitution and violence have also increased, with sex workers coming from as far as Mutare and Chimanimani [about 100km southeast of Mutare] to waylay the free-spending makorokoza, who turned Marange shopping centre [in Marange town] into a very busy spot," said Mharidzo.

With security tight in the towns of Buhera and Marange, some buyers were involving "those who matter" to successfully carry out their illegal business. "You ought to be close to the big guys in the army and police and bribe them for you to be let to pass," said Isaac Moyo, who owns two gold claims in the small mining town of Shamva in Mashonaland Central Province but is also buying diamonds in Marange.

He moves in and out of the area with ease, and said some soldiers and police officers were confiscating emeralds and diamonds from illegal traders, and working with officials at the Beitbridge border post, the main crossing between South Africa and Zimbabwe, who would then smuggle the minerals to Musina in South Africa.

Economist Makwiramiti said the widespread panning for minerals was a direct result of an ill-performing economy and rising poverty. "Gold panning became rampant in the early 1990s, following a devastating drought and the introduction of an economic structural adjustment programme that impoverished the people."

Another economist, John Robertson, said the country was losing its precious minerals to other countries through smuggling because the government had an unrealistic foreign currency exchange rate. "The government is using the wrong exchange rate - thus the easy smuggling of minerals out of the country, where sellers fetch more," he told IRIN.

While the US dollar, when available, is being sold at the official rate of Z$250, on the parallel market the exchange rate is as much as Z$3,000 to the US dollar.

In November 2006 the police launched Operation Chikorokoza Chapera [End of Illegal Mining], and to date have arrested about 22,500 illegal miners, recovered 7,799 diamonds and 3.5kg of gold worth about Z$60 million (US$240,000), as well as 544,231kg of gold ore, 1,872kg of quartz, 25,000kg of chrome and 80 emeralds.

A Belgian national was among those arrested for illegally buying diamonds in Zimbabwe, but has since been acquitted by the courts.

The European Union recently expressed concern over claims that diamonds smuggled out of the country were being sold on the world market, adding that if the allegations were verified, Zimbabwe could face a ban on the sale of all its precious minerals.