Seven deaths have been attributed to the waste, although autopsies have yet to confirm the cause. Ivorian emergency medical service officials said more than 44 000 people have gone to hospitals and clinics for evaluation, but it was unclear how many of them were seeking treatment for exposure to the toxic sludge or for unrelated ailments to take advantage of a government offer of free medical treatment.

Sixty-six people have been referred for further medical evaluation, medical service officials said.

Living conditions in Cote d’Ivoire have deteriorated since civil war erupted in September 2002, leaving the country divided between a rebel-held north and government-held south.

A United Nations-brokered peace agreement is under threat as president Laurent Gbagbo’s term expires at the end of October with no clear indication who will lead the country thereafter.

The clean-up team, from the France-based Seche group, early Sunday began pumping the hazardous black sludge from Abidjan’s main garbage dump. It was among the most contaminated of at least 10 dumpsites across the city.

The operation was expected to take several weeks, officials said.

“This is dangerous stuff,” said Henri Petitgand, a spokesperson for the Seche group. “People should not get near it without protective gear.”

The chemical waste arrived in Abidjan, a port city, last month on a ship chartered by the Netherlands-based commodities company Trafigura Beheer and apparently dumped in residential neighbourhoods by a local contractor. The substance contains the potentially lethal hydrogen sulfide, according to a UN report.

The waste scandal added to an already politically charged atmosphere in Abidjan. Residents on Saturday attacked the transport minister and set fire to the home of the general manager of the Abidjan port, accusing them of being involved in the waste dumping.

The government resigned nearly two weeks ago after the waste scandal broke. A new, larger Cabinet was announced on Saturday, but there were effectively few changes.

All ministers were reappointed to their same posts, except for the ministers of transport and environment. The interior ministry was split into security and territorial portfolios, and two new secretaries of state for human rights and good governance were added.

Prime minister Charles Konan Banny told IRIN that the transport minister had been replaced because he had delivered permits - or permits had been delivered under him - “which are connected to this affair”.

The environment minister was withdrawn by his own party, Banny said.

He said it was possible that bribes had been paid to dump the toxic waste.

"I don't think that these operations are done without money changing hands. There is probably a corruptor and someone who has been corrupted somewhere," he added.

The government has begun an investigation into the waste scandal and suspended a number of high-ranking officials, including the general manager of the Abidjan port and the head of customs.

The waste was discovered by residents who began complaining of a nauseating stench and persistent health problems such as vomiting, breathing difficulties and headaches.

"There is a lot of fear and that’s normal. The population has a good reason to be angry because people are suffering,” Banny said. “At the same time, people should not be too worried because we now know what the nature of the waste is and because we have taken measures to help them.”

The waste is being pumped into vats and will be shipped back in secured containers to a European country for destruction.

Donor countries are helping pay the Cote d’Ivoire government for the clean-up operation but Banny said whoever was found responsible for the dumping was expected to reimburse the costs.

“The Basel Convention stipulates that the polluter must pay,” he said.

The international Basel agreement was signed in 1989 to protect poor countries from the dumping of hazardous waste and stipulates that the source country for any waste illegally discharged must pay for its removal. www.irinnews.org