A lawsuit filed by three Vietnamese citizens against the makers of the defoliant Agent Orange has been expanded after nearly 100 more people - who say the chemical has made them ill - joined the case.

A lawsuit filed by three Vietnamese citizens against the makers of the defoliant Agent Orange has been expanded after nearly 100 more people - who say the chemical has made them ill - joined the case.

Two women and a man filed the suit on 30 January in New York, seeking damages from more than 20 companies that produced the chemical, which US forces sprayed on Vietnam nearly 30 years ago.

It was the first legal redress ever sought by Vietnamese victims.

The additional names have been forwarded to US lawyers representing the Vietnamese claimants.

Agent Orange, named after the colour of its containers, was made by a number of companies including Dow Chemical and Monsanto, which were named in the suit. The chemical destroyed the jungles that Communist forces used for shelter and growing food.

American veterans of the Vietnam War exposed to the herbicide have complained for years about a variety of health problems and have also sued the makers.

In 1984, Dow and Monsanto agreed to pay $180m to US veterans.

Among the chemical components of Agent Orange was dioxin, a compound that remains in the soil and is shown to cause cancer, birth defects and organ dysfunction.

The after-effects of Agent Orange remain a sticking point in the US-Vietnam relationship. Both sides are conducting research on the defoliant, but Washington has consistently declined to discuss compensation.