A ship that has been unable to unload its 10,000 tons of ash for 20 months is headed for West Africa, where public anger is rising at industrial nations trying to dump wastes. The Khian Sea is en route to the Cape Verde Islands, and from there it will go to an undisclosed destination in West Africa, said its operator, the Amalgamated Shipping Co. of Freeport, the Bahamas. In a June 3 letter to the Environmental Protection Agency, Amalgamated Shipping said the Khian Sea was proceeding ``under reduced speed'' to the islands west of Senegal to await further orders. The company said it had a representative in West Africa negotiating for the discharge of the ash, which came from city incinerators. The Organization of African Unity has called plans by developed countries to dump their wastes ``a crime against Africa and Africans,'' and the Greenpeace environmental group said in a report last week that shipping waste to Africa was a growing trend. ``In particular, Africa, the Caribbean and Latin America have become the preferred dumping grounds of waste peddlers from industrialized countries,'' Greenpeace said. On Thursday, Guinean officials announced that they had jailed a Norwegian official and several Guinean employees of the Ministry of Commerce for bringing 15,000 tons of Philadelphia ash into the country. ``If the Khian Sea is planning to go to West Africa, if these guys are thinking of marketing their material there, their timing is way off,'' said Peter Christich, an official in the EPA's international affairs office. The Khian Sea left Philadelphia in October 1986 loaded with about 15,000 tons of incinerator ash. It has been rejected by the Bahamas, the Dominican Republic, Honduras, Haiti and Guinea-Bissau. It unloaded about 4,000 tons of ash in Haiti before being ordered out of the country. It returned to the Delaware Bay on March 1 with the intention of taking the ash back to Philadelphia. But negotiations broke down with the contractor who was to dispose of the ash, Joseph Paolino & Sons, and the ship left May 22. In March, A.S. Bulkhandling, Inc., a Norwegian shipping company, said it had taken 15,000 tons of Philadelphia incinerator ash to Guinea to be used in making construction material. The ash was dumped on the island of Kassa, off the Guinean coast. By May, the Guinean government formally requested that the ash be removed. Bulkhandling officials tried to convince the government that the ash was not harmful, but it was not convinced and set a May 20 deadline to remove the ash. The ash was not taken away, and on Thursday, the government announced that Norway's consul general had been arrested for complicity in the secret dumping of what it called 15,000 tons of toxic waste from the United States. Ibrahima Sory Diaby, Guinean secretary of state for security, said the waste was shipped from Philadelphia. City officials have said that the ash is not harmful.