Here is a chronology of events surrounding the scandal over the past week.

- September 4: Scores of people fall sick, some of them seriously from inhaling poisonous fumes from toxic chemical waste dumped two weeks earlier. Government admits toxic waste dumped at several open-air sites in Abidjan.

- September 5: Two girls die from respiratory problems arising from inhaling the toxic fumes. Prime Minister Charles Konan Banny admits situation "more serious" than thought.

- September 6 : Accepting negligence over the case, entire Ivory Coast government resigns as death toll jumps to three and 1,500 poisoned. A Greek company that owns Probo Koala, Prime Marine Management, confirms the ship -- chartered by Netherlands-based oil trading firm Trafigura -- had discharged toxic waste in Abidjan. Both firms deny responsibility, saying discharge was lawful as Ivorian company was entrusted with its disposal.

Environmental pressure group Greenpeace says 400 tonnes of oil refining waste, rich in organic matter and very toxic elements, was dumped at about 10 sites across the city of four million people.

Abidjan Port authority accuse transport ministry, which says ship obeyed all rules, of authorising the unloading of some 531 tonnes of the poisonous chemicals.

- September 8: French waste disposal experts start arriving to help solve the crisis.

- September 9: Number of poisoned rise to 5.000

- September 10: Poisoning toll rises to five dead and at least 6,000 sickened.

- September 11: Poisoning toll urges up to nearly 9.000 people and six deaths. Seven people arrested over the case. UN sends its experts to help out.