 Yet with the <unk> Tuy province coming progressively under control throughout 1967 , the Australians increasingly spent a significant period of time conducting operations further afield . 1 <unk> was subsequently deployed <unk> infiltration routes leading to Saigon to <unk> communist movement against the capital as part of Operation <unk> during the 1968 <unk> Offensive and later during the Battle of Coral – <unk> in May and June 1968 . At Fire Support <unk> Coral and <unk> the Australians had clashed with regular North Vietnamese Army and Viet Cong main force units operating in battalion and regimental strength for the first time in near conventional warfare , ultimately fighting their largest , most hazardous and most sustained battle of the war . During 26 days of fighting Australian casualties included 25 killed and 99 wounded , while communist casualties included 267 killed confirmed by body count , 60 possibly killed , 7 wounded and 11 captured . Other significant Australian actions included Binh Ba in June 1969 , <unk> <unk> in late @-@ December 1968 and early 1969 and Long <unk> in June 1971 . At the height of the Australian commitment , 1 <unk> numbered 8 @,@ 500 troops , including three infantry battalions , armour , artillery , engineers , logistics and aviation units in support . A third RAAF unit , No. 2 Squadron RAAF , flying Canberra bombers , was sent in 1967 , and four <unk> destroyers joined US patrols in the waters off North Vietnam . 
