The 600-mile Essequibo was polluted with about 825 million gallons of cyanide-treated wastewater from the huge pond. Cyanide is used to separate fine flakes of gold from other materials in the second stage of the mining process. The solid hydrogen cyanide salt used in gold processing is highly toxic, and the Associated Press reported that it can be deadly in concentrations as small as 2 parts per million.

The mine's owners said there was no major damage done to the river and no evidence of loss of animal or aquatic life in the Essequibo, a claim that few took at face value. A report in the English-speaking nation's major daily newspaper, the Guyana Chronicle, and earlier reports carried by the Associated Press, say shoals of dead fish and hogs had floated downstream on the Essequibo to Bartica, a mining village of 15,000 people some 50 miles south of the mine, South America's largest.

President Jagan told newsmen last week that it wasn't the first leak of cyanide from the tailings pond. Tailings are chemically -treated debris from the mining process that at Omai were contained in a vast pool of contaminated water the size of a small lake.

"I am indeed alarmed at the repeated incidence of a major spillage at the Omai Gold Mine, just three months after the first reported spillage at the same site," the president said in Georgetown.

"Immedediately, the government dispatched a special team to the site to make an independent assessment of the situation."

A special monitoring team which includes regional authorities has been set up and samples of fish and other marine life are being analyzed. The ministry of health has its own teams in the area to prevent the sale and consumption of fish caught in the river at points between Omai and Bartica.

Steps are also being taken to inform native Indians and other communities in the jungle of the disaster and the need to take precautionary measures -- but the authorities say it could take weeks to get through dense jungle.

President Jagan issued a radio appeal not to drink water from the Omai or Essequibo rivers as dangerous levels of cyanide continue to flow downriver.

Prime minister Sam Hinds has met with Omai mine executives with the crucial objective to stop or stem the flow of pollutant into the Omai river which discharges into the Essequibo. Emergency agencies in the area have been instructed to spare no efforts or resources to control the catastrophe.

Guyana's government, overloaded with international debt and already in a state of bankruptcy, does not have the financial or technological means to cope with the cyanide flow, which has already reached the open waters of the Atlantic, potentially causing more damage to rich fishing waters of South America. Most of the cyanide is expected to evaporate, however.

A full parliamentary debate was scheduled to begin when the national assembly met in Georgetown, and opposition parties have been invited to join a national consensus on government measures. Among other things, consultations on an Environmental Act awaitying passage are to be speeded up and mechanisms for environmental protection established swiftly, Jagan said.

President Jagan admitted that many control functions are outside the government's present capacity due to their cost, and will take longer to implement than the present ecological protections.

"Equally, we must protect our rainforests from loggers who are cutting trees down in large-scale operations where we are also faced with massive costs to control what's happening within our territory," he said. He had declared the area a Disaster Zone, saying but it was impossible to give exact boundaries because the disaster is on such a large scale.

Concluding his rare radio broadcast, the president pledged to bring the Omai Gold Mine's Canadian owners to trial. "Omai had the responsibility to take environmental precautions and the government has the responsibility and the commitmehe Guyanese nation."

Meanwhile, the Canadian owners said a design failure caused the catastrophe and have issued statements denying that any negligence on the part of the company.

"There was no disaster," Omai deputy general manager Claude Dumont insists. "The amount of sodium cyanide released into the Omai river was insignificant. When the government began yelling its head off about river pollution, you would have thought we were consciously tipping cyanide concentrate into the river -- it just isn't so.

"By the time the government inspection teams got [to the mine], there were no dead fish in sight -- what happened is peanuts. It was an unfortunate incident. We have to live with, but it doesn't have the dimensions the government are putting on it. And, anyway, Guyana doesn't have a workable environmental protection law or any monitoring mechanism. Nevertheless, I repeat, it was just peanuts."

On-site critics say the Guyanese government saw the international opportunity to earn "big bucks" from a gullible international community when, in fact, negotiations were underway with the government to allow the Omai mine to release 20 times the amount of cyanide tailings into the Essequibo six months earlier than ordinarily planned. The government owns five percent of the mine.

Joshua Ramsammy, a biologist for the private Guyana Monitoring and Conservation Organization, confirmed the mine's analysis and said Prime Minister Sam Hinds' government faces re-election next year and desperately needs money from the mine to cover crippling international debt obligations. The nation pays as much as 80 percent of its tax revenues to foreign lenders on $2.1 billion in foreign debt.

Omai Gold Mines Ltd., a company owned by Canadian-based Cambior, Inc., and the Golden Star Resources Ltd. operating subsidiary of Denver- based Invesco PLC, will be closed for six months as a result of the disaster, sources told the American Reporter news service. It could not be learned if the mine was insured for the disaster.

Invesco PLC runs a number of funds specialized in medium-risk companies in developing nations, and warn investors of the danger of losses. FMR Corp., better known as the Fidelity Funds, was listed with the Security and Exchange Commission as owner 165,000 shares of Golden Star before Sunday's disaster. The mine produced an estimated 88,000 ounces of gold in 1994.