Complex sentence: The Viet Cong withdrew rapidly south-east, and although the Australians believed it to be just another fleeting contact artillery fire from 161st Battery, RNZA was called-in on the likely withdrawal route to the south.
Split into simpler sentences: The Viet Cong withdrew rapidly south-east, and the Australians believed it was just another fleeting contact. Artillery fire from 161st Battery, RNZA was subsequently called-in on the likely withdrawal route to the south.