Victims with symptoms ranging from breathing difficulties to nosebleeds described scenes of chaos and a shortage of essential medicines.

“People are waiting all day in these queues, arriving in the early morning and only leaving the hospitals at night,” said Florentine Coulibaly, a patients’ spokeswoman. “Even with all the medicines administered, people are going home and their illness is continuing.”

Residents of Abidjan, known as the Paris of west Africa, began to complain of a smell of rotten eggs last month, shortly after the Greek-registered Probo Koala discharged a poisonous mix of petrol wastes and cleaning agents, known as slops, from its tanks. The sludge was taken away by a local company and dumped at 10 sites around the city.

Within days at least three children were dead from the fumes and the number of people affected has continued to rise sharply. Angry protesters used burning tyres and logs to block roads leading to areas where the waste had been dumped.

Some of the waste, which contains chlorine compounds and hydrogen sulphide — the source of the rotten eggs smell — was dumped in ditches in residential areas. Exposure has led to headaches, stomach pains, vomiting and unconsciousness. Doctors say that many patients have returned to hospital several times, since most of those discharged had no choice but to return to their homes near the waste sites.

“It is a catastrophe,” said Simeon N’Da, a health ministry spokesman. He said 23 people were in a serious condition this weekend.

The United Nations and France have sent teams of experts to help deal with the crisis. But a report last week warned that the food chain may be contaminated after some of the waste was dumped in lagoons and the sea.

A Dutch firm that chartered the ship, Trafigura Beheer BV, said: “The company is appalled at what has happened to the health of the people of Abidjan as a result of this incident.”

It said the waste had been given to an Ivorian firm, Compagnie Tommy, for disposal. The Ivorian government has arrested seven people in connection with the scandal, including officials from the local company.

A previous attempt to unload the waste in Amsterdam had failed after the specialist handler, Amsterdam Port Services, decided that it was so highly toxic that higher fees would be required to process it. The Probo Koala left Europe for Africa still loaded with the poisons.

The Ivorian government resigned over the scandal, throwing into confusion a fragile peace process that has been maintained since the 2002-03 civil war. President Laurent Gbagbo yesterday named a new cabinet, dropping his environment and transport ministers, both of whom have come under heavy criticism.

“It complicates the situation greatly . . . this is a political crisis,” said Alex Vines, head of the Africa programme at Chatham House and chairman of a UN panel of experts on the Ivory Coast.

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