MANAGUA - (EFE) -- Several hundred former farm workers in western Nicaragua who were negatively affected in the 1970s by the pesticide Nemagon began a long protest march over the weekend.

  Organizers of the event -- which covers 90 miles and is expected to end Feb. 10 -- told the local press Sunday that it is the farm workers' third march to press the
  Nicaraguan government to support their class-action lawsuit against the U.S. Shell Oil Co., Shell Chemical Co. and the Dow Chemical Co.

  Several thousand agricultural laborers are suing the companies for damages and medical problems resulting from their exposure to the chemical used on banana
  plantations in the western part of the country.

  The protest march was begun in the towns of El Viejo and Chinandega, and on Sunday -- after a night's rest in Chichigalpa -- moved on toward Posoltega and Leon, 56
  miles west of Managua, organizers said.

  Each of the former banana plantation workers is suing for $2 million in damages in both U.S. and Nicaraguan courts. The total damages sought amount to $17 billion.

  Once in the capital, the marchers will gather outside the presidential residence, Congress and the Supreme Court to press the government for protection under a law
  passed in 2000 aimed at preventing U.S. companies from evading the lawsuits.