South Vietnamese armoured units have been carrying out an operation close to the Demilitarised Zone bordering North Vietnam. Their job was to flush out a battalion of North Vietnamese infiltrators.

Armoured personnel carriers and T-41 tanks moved across the rolling terrain that three years ago was the scene of some of the most vicious fighting in the Vietnam war as both sides traded blows across the border.

After the tanks pounded suspected Viet Cong positions during the latest operation, the infantry moved in aboard the personnel carriers. All of them were South Vietnamese soldiers, reflecting the growing "Vietnamisation" of the war.

The South Vietnamese concentrated on a clump of long grass where they believed Communist bunkers were situated. They warily approached the position, firing as they went.

Their suspicions were correct, though only one North Vietnamese was found. Later four others were killed and several North Vietnamese weapons captured.