O'SMACH, Aug 12: A brilliant flash and a thundering explosion rip the peace of a dirt road snaking through Cambodia's dense northern jungles.But before the sound even registers, Chea Mai crumples to the ground, his abdomen mangled by hot shrapnel.

He has triggered an invisible trip wire, detonating a mortar round rigged as a booby trap along the road while he marched headlong into enemy-held terrain.

In Cambodia's newest guerrilla war, the latest horror in the nation's two decades of bloodshed, coups and genocide, there are no rules of engagement, no Geneva conventions. In this war, anything goes.

A 24-year-old soldier in the army of Hun Sun, who seized power in a bloody July 5-6 coup, Chea Mai was cut down in a chaotic two-hour skirmish in a remote place few have heard of, in a war many can't be bothered with.

He and his compatriots were battling two enemies at the sametime: Royalist soldiers loyal to ousted first prime minister Prince Norodom Ranariddh and the remnants of Khmer Rouge rebels.

Chea Mai was the first casualty of the battle.

Two fellow soldiers rushed in to help, bundling him into a hammock slung from a long pole. They dashed off, rubber sandals flapping against the ground, hauling him to a distant aid station.

He looked up from under a blood-soaked blanket and tried to speak, but only blood came from his mouth. A few paces further, his eyes rolled back into his head. Three more steps and Chea Mai was dead.

But while Chea Mai did not survive this battle, it is the opposition that may be facing the end, with the government warning it is massing for a final assault on the royalists. Ranariddh, though, insists they are far from defeated.

Resistance fighters loyal to Ranariddh, who have been on the run since the coup, are trapped in a desperate bid to hold off government troops.With Hun Sen's forces fast approaching O'Smach, the royalists'last outpost just across the border from Thailand, the resistance is fighting just to survive. Outnumbered and cut off from supplies, they have aligned themselves with what remains of the Khmer Rouge.

After they seized power in 1975, the Khmer Rouge guerrillas turned Cambodia into a Maoist-inspired labour camp and caused the deaths of as many as 2 million people.

They detest Hun Sen, a former Khmer Rouge member who escaped purges in 1977 and allied himself with the country's historic enemy, Vietnam. Vietnam's army toppled the Khmer Rouge regime in 1979, and Hun Sen eventually came to lead the Vietnam-backed government of the 1980s.

Though their numbers have dwindled, Khmer Rouge rebels, with Chinese-style Mao caps and a grim, ruthless fighting style, are still dreaded opponents.

Copyright © 1997 Indian Express Newspapers (Bombay) Ltd.