CIA's secret war is revealed as Laos jails European journalists

International diplomatic efforts are under way to secure the release of two respected European journalists who were this week given 15-year prison sentences after setting out to explore a remarkable forgotten legacy of the CIA's covert operations in the Vietnam War.

The harsh sentences passed in Laos against the Belgian reporter Thierry Falise, 46, Vincent Reynaud, a 38-year-old French photographer, and their translator Naw Karl Mua - an American citizen - have outraged human rights activists and journalists.

But the affair has also proved counter-productive for the Lao authorities - who preside over one of the world's last surviving Communist regimes - by throwing a spotlight on a murky conflict that they prefer to deny exists.

The journalists, who entered the country on tourist visas, were researching the fate of ethnic Hmong who were hired by the CIA during the Vietnam War to fight on the side of the Americans against the Communists.

At the height of the conflict, more than 30,000 Hmong were engaged in what became known as America's "secret war" against the North Vietnamese and Communist Pathet Lao. Small pockets of them - hiding in the jungle and mountains of the north - have continued fighting; it appears they are still waiting for the Americans to come to their aid.

In the last five months, reports from Xaysomboune militarised zone - the jungle- bound northern area where they operate - suggest that they have carried out at least three attacks on buses, killing more than 30 people.

Several years ago the Lao government began a fresh military drive to flush the Hmong fighters out and eradicate them. According to Grant Evans, an expert on Laos, the conflict is no longer driven by ideology, but rather is fuelled by rivalry and tit-for-tat attacks involving the insurgents and local army commanders.

The few people who have managed to reach the Hmong have returned with accounts of a desperate rag-tag band of fighters, living on yams, tree roots and wild potatoes, and equipped with the same guns that they used in the 1960s and 1970s.

Supported by Hmong exiles in the US, the guerrillas, who number several thousand, are thought mostly to comprise the children and relatives of the CIA's original secret army.

In December 2001, three Americans, led by a retired Los Angeles detective, went to the area to try to gather information about their fate. They belong to a California-based organisation called the Fact-Finding Commission, which is pressing the US government to negotiate safe passage for the beleaguered fighters, to repay their loyalty. But they say there has been no sign of interest from Washington.

The three subsequently presented a report to the US Congress which said: "When the United States pulled out of the war in Vietnam and left South-east Asia [in 1975], we left the Hmong, Mien, Khamu, and Lao soldiers who fought in the CIA-sponsored Secret Army of Laos to fend for themselves."

The report alleged that Lao and Vietnamese forces were "systematically exterminating" them, and warned that "without immediate intervention" there was "little hope" for these people.

The Fact-Finding Commission drew a harrowing picture of an ill-armed and tattered force, moving steathily around the mountains and facing starvation, not least because of dwindling supplies of yams.

"For 26 years these people have lived in the jungle holding on to the hope that their American allies would come to their rescue," the report stated. It said this was their first contact with Americans for more than a quarter of a century.

Two Time magazine journalists managed to reach the guerrillas earlier this year, and returned with pictures of emaciated fighters, weeping and begging on their knees for their help.

The Lao government denies the existence of the insurgent army, blaming the sporadic attacks on civilians and skirmishes with troops on "bandits".

Analysts say that Laos has recently been working to improve relations with the nation's Hmong minority, of whom the fighters are a tiny part.

But it is clearly a hugely sensitive issue for the Communist government, as the two journalists and their translator discovered.

Discussions between the Lao government, and US, French and Belgian officials are under way, amid hopeful signs that the correspondents - officially convicted on charges of being involved in the death of a village security guard - may soon return to tell their story.

Laos's Foreign Minister has said that they may soon be freed if their governments petition to have their sentences commuted. And its ambassador to France has also said that they would be free "within a matter of days".

The European Parliament on Friday adopted a resolution calling for the immediate release of the two European journalists and condemning the deterioration of the human rights situation in Laos.