 " .   Two days later , on 17 May , the 57th / 60th Infantry Battalion began its diversionary move on the left flank , crossing the Hongorai inland and advancing along the Commando Road with 32 Corsairs and two batteries of artillery in support . Crossing 500 yd ( 460 m ) north of the ford , the centre company carried out an attack along the far bank of the river without its armoured support which had been unable to negotiate the crossing . Nevertheless , shortly before noon they had secured the crossing and began to fan out , carrying out further flanking moves before establishing a firm base to receive supplies and from where it began patrolling operations on 20 May .   In the centre , the main attack along the Buin Road began at 08 : 30 on 20 May after 20 minutes of strafing by New Zealand Corsairs had prepared the ground . Advancing under a creeping barrage , and with mortar and machine gun support , the 24th Infantry Battalion moved forward with three companies up front and one held back in reserve , along with two troops of Matilda tanks . Mostly the forward companies reached their objectives , but one of the companies was halted just short of their objective and was forced to dig @-@ in overnight after coming under heavy small arms and artillery fire and losing four killed and five wounded . The attack was resumed the following day , and the Australians were able to advance to the Pororei ford ; however , they were prevented from moving any further as the Japanese were still concentrated in large numbers further to the west where an Australian patrol encountered 70 Japanese and were forced to go to ground . Finally , a company from the 24th Infantry Battalion was able to move on to the high ground on Egan 's Ridge , which they found to be heavily mined and booby trapped . Engineers and assault pioneers were called up to clear the feature .   On the right flank , the 58th / 59th Infantry Battalion carried out a wide flanking move along a track that had been carved out of the west bank of the Hongorai by bulldozer . Beginning their move two days earlier , a number of patrols had had contacts with the Japanese . Meanwhile , using tractors to drag the tanks through the mud , the Australian armour had crossed the river also and by 16 : 00 on 20 May the battalion had managed to establish itself in an assembly area to the east of the river , unbeknown to the Japanese . The following day , the battalion left the line of departure and began to advance on its primary objective , which it reached in the early afternoon despite being held up while the tanks attempted to affect a creek crossing , and further delayed by stiff resistance . Later , after one of the battalion 's patrols came under heavy fire , the tanks moved up and attacked a Japanese gun position which the defenders quickly abandoned , leaving behind a 70 mm gun and a large amount of ammunition .   By 22 May , although there were still a number of Japanese in the area which continued to harass and ambush their line of communications , most of the Australian objectives had been secured and mopping up operations began . The last remaining defensive location before the Hongorai was Egan 's Ridge , where the Japanese were sheltering in tunnels . A heavy aerial and artillery bombardment devastated the position and forced them to abandon the ridge . It was subsequently occupied by a company of Australian infantry . Within a short period of time the Buin Road was subsequently opened , providing the Australians with the means with which to bring up supplies for the next stage of the campaign , being the advance to the Hari , Mobiai , and Mivo Rivers . The final phase of the battle cost the Japanese 106 killed , while the Australians lost 13 killed and 64 wounded .   = = Aftermath = =   During the course of the fighting around the Hongorai , the Australians lost 38 men killed and 159 wounded , while the Japanese lost at least 275 men killed . Following the battle , the Australians continued their advance towards Buin at the southern end of the island . Throughout the remainder of the month and into June , the 15th Brigade advanced along the Buin Road , crossing the Hari on 10 June . Beyond the river , the Japanese resolved to hold the food growing areas in order to protect their precarious food supply , and they consequently occupied a series of deep entrenchments . These were steadily reduced with airstrikes and artillery , and the 15th Brigade subsequently crossed Mobiai River before being relieved by Brigadier Noel Simpson 's 29th Brigade in early July .   As the 29th Brigade advanced toward the Mivo River , torrential rain and flooding ultimately brought the advance to a halt . The height of the river rose 2 metres ( 6 @.@ 6 ft ) . The Buin Road was reduced , in the words of Gavin Long , " to a sea of mud " and many of the bridges upon which the Australian supply system was dependent were washed away . This rendered large @-@ scale offensive infantry operations impossible and as the situation worsened for a period of time the Australians even ceased patrolling operations across the
Ġ" Ġ. Ġ Ġ ĠTwo Ġdays Ġlater Ġ, Ġon Ġ17 ĠMay Ġ, Ġthe Ġ57 th Ġ/ Ġ60 th ĠInfantry ĠBattalion Ġbegan Ġits Ġdiversion ary Ġmove Ġon Ġthe Ġleft Ġflank Ġ, Ġcrossing Ġthe ĠHong or ai Ġinland Ġand Ġadvancing Ġalong Ġthe ĠCommando ĠRoad Ġwith Ġ32 ĠCors airs Ġand Ġtwo Ġbatteries Ġof Ġartillery Ġin Ġsupport Ġ. ĠCrossing Ġ500 Ġy d Ġ( Ġ460 Ġm Ġ) Ġnorth Ġof Ġthe Ġfor d Ġ, Ġthe Ġcentre Ġcompany Ġcarried Ġout Ġan Ġattack Ġalong Ġthe Ġfar Ġbank Ġof Ġthe Ġriver Ġwithout Ġits Ġarmoured Ġsupport Ġwhich Ġhad Ġbeen Ġunable Ġto Ġnegotiate Ġthe Ġcrossing Ġ. ĠNevertheless Ġ, Ġshortly Ġbefore Ġnoon Ġthey Ġhad Ġsecured Ġthe Ġcrossing Ġand Ġbegan Ġto Ġfan Ġout Ġ, Ġcarrying Ġout Ġfurther Ġfl anking Ġmoves Ġbefore Ġestablishing Ġa Ġfirm Ġbase Ġto Ġreceive Ġsupplies Ġand Ġfrom Ġwhere Ġit Ġbegan Ġpatrolling Ġoperations Ġon Ġ20 ĠMay Ġ. Ġ Ġ ĠIn Ġthe Ġcentre Ġ, Ġthe Ġmain Ġattack Ġalong Ġthe ĠBu in ĠRoad Ġbegan Ġat Ġ08 Ġ: Ġ30 Ġon Ġ20 ĠMay Ġafter Ġ20 Ġminutes Ġof Ġstra fing Ġby ĠNew ĠZealand ĠCors airs Ġhad Ġprepared Ġthe Ġground Ġ. ĠAdv ancing Ġunder Ġa Ġcreeping Ġbarrage Ġ, Ġand Ġwith Ġmortar Ġand Ġmachine Ġgun Ġsupport Ġ, Ġthe Ġ24 th ĠInfantry ĠBattalion Ġmoved Ġforward Ġwith Ġthree Ġcompanies Ġup Ġfront Ġand Ġone Ġheld Ġback Ġin Ġreserve Ġ, Ġalong Ġwith Ġtwo Ġtroops Ġof ĠMat ilda Ġtanks Ġ. ĠMostly Ġthe Ġforward Ġcompanies Ġreached Ġtheir Ġobjectives Ġ, Ġbut Ġone Ġof Ġthe Ġcompanies Ġwas Ġhalted Ġjust Ġshort Ġof Ġtheir Ġobjective Ġand Ġwas Ġforced Ġto Ġdig Ġ@ - @ Ġin Ġovernight Ġafter Ġcoming Ġunder Ġheavy Ġsmall Ġarms Ġand Ġartillery Ġfire Ġand Ġlosing Ġfour Ġkilled Ġand Ġfive Ġwounded Ġ. ĠThe Ġattack Ġwas Ġresumed Ġthe Ġfollowing Ġday Ġ, Ġand Ġthe ĠAustralians Ġwere Ġable Ġto Ġadvance Ġto Ġthe ĠPor ore i Ġfor d Ġ; Ġhowever Ġ, Ġthey Ġwere Ġprevented Ġfrom Ġmoving Ġany Ġfurther Ġas Ġthe ĠJapanese Ġwere Ġstill Ġconcentrated Ġin Ġlarge Ġnumbers Ġfurther Ġto Ġthe Ġwest Ġwhere Ġan ĠAustralian Ġpatrol Ġencountered Ġ70 ĠJapanese Ġand Ġwere Ġforced Ġto Ġgo Ġto Ġground Ġ. ĠFinally Ġ, Ġa Ġcompany Ġfrom Ġthe Ġ24 th ĠInfantry ĠBattalion Ġwas Ġable Ġto Ġmove Ġon Ġto Ġthe Ġhigh Ġground Ġon ĠE gan Ġ' s ĠRidge Ġ, Ġwhich Ġthey Ġfound Ġto Ġbe Ġheavily Ġmined Ġand Ġbo oby Ġtrapped Ġ. ĠEngineers Ġand Ġassault Ġpioneers Ġwere Ġcalled Ġup Ġto Ġclear Ġthe Ġfeature Ġ. Ġ Ġ ĠOn Ġthe Ġright Ġflank Ġ, Ġthe Ġ58 th Ġ/ Ġ59 th ĠInfantry ĠBattalion Ġcarried Ġout Ġa Ġwide Ġfl anking Ġmove Ġalong Ġa Ġtrack Ġthat Ġhad Ġbeen Ġcarved Ġout Ġof Ġthe Ġwest Ġbank Ġof Ġthe ĠHong or ai Ġby Ġbulldo zer Ġ. ĠBeginning Ġtheir Ġmove Ġtwo Ġdays Ġearlier Ġ, Ġa Ġnumber Ġof Ġpatrols Ġhad Ġhad Ġcontacts Ġwith Ġthe ĠJapanese Ġ. ĠMeanwhile Ġ, Ġusing Ġtract ors Ġto Ġdrag Ġthe Ġtanks Ġthrough Ġthe Ġmud Ġ, Ġthe ĠAustralian Ġarmour Ġhad Ġcrossed Ġthe Ġriver Ġalso Ġand Ġby Ġ16 Ġ: Ġ00 Ġon Ġ20 ĠMay Ġthe Ġbattalion Ġhad Ġmanaged Ġto Ġestablish Ġitself Ġin Ġan Ġassembly Ġarea Ġto Ġthe Ġeast Ġof Ġthe Ġriver Ġ, Ġunb ek nown Ġto Ġthe ĠJapanese Ġ. ĠThe Ġfollowing Ġday Ġ, Ġthe Ġbattalion Ġleft Ġthe Ġline Ġof Ġdeparture Ġand Ġbegan Ġto Ġadvance Ġon Ġits Ġprimary Ġobjective Ġ, Ġwhich Ġit Ġreached Ġin Ġthe Ġearly Ġafternoon Ġdespite Ġbeing Ġheld Ġup Ġwhile Ġthe Ġtanks Ġattempted Ġto Ġaffect Ġa Ġcreek Ġcrossing Ġ, Ġand Ġfurther Ġdelayed Ġby Ġstiff Ġresistance Ġ. ĠLater Ġ, Ġafter Ġone Ġof Ġthe Ġbattalion Ġ' s Ġpatrols Ġcame Ġunder Ġheavy Ġfire Ġ, Ġthe Ġtanks Ġmoved Ġup Ġand Ġattacked Ġa ĠJapanese Ġgun Ġposition Ġwhich Ġthe Ġdefenders Ġquickly Ġabandoned Ġ, Ġleaving Ġbehind Ġa Ġ70 Ġmm Ġgun Ġand Ġa Ġlarge Ġamount Ġof Ġammunition Ġ. Ġ Ġ ĠBy Ġ22 ĠMay Ġ, Ġalthough Ġthere Ġwere Ġstill Ġa Ġnumber Ġof ĠJapanese Ġin Ġthe Ġarea Ġwhich Ġcontinued Ġto Ġharass Ġand Ġambush Ġtheir Ġline Ġof Ġcommunications Ġ, Ġmost Ġof Ġthe ĠAustralian Ġobjectives Ġhad Ġbeen Ġsecured Ġand Ġmo pping Ġup Ġoperations Ġbegan Ġ. ĠThe Ġlast Ġremaining Ġdefensive Ġlocation Ġbefore Ġthe ĠHong or ai Ġwas ĠE gan Ġ' s ĠRidge Ġ, Ġwhere Ġthe ĠJapanese Ġwere Ġshelter ing Ġin Ġtunnels Ġ. ĠA Ġheavy Ġaerial Ġand Ġartillery Ġbombardment Ġdevastated Ġthe Ġposition Ġand Ġforced Ġthem Ġto Ġabandon Ġthe Ġridge Ġ. ĠIt Ġwas Ġsubsequently Ġoccupied Ġby Ġa Ġcompany Ġof ĠAustralian Ġinfantry Ġ. ĠWithin Ġa Ġshort Ġperiod Ġof Ġtime Ġthe ĠBu in ĠRoad Ġwas Ġsubsequently Ġopened Ġ, Ġproviding Ġthe ĠAustralians Ġwith Ġthe Ġmeans Ġwith Ġwhich Ġto Ġbring Ġup Ġsupplies Ġfor Ġthe Ġnext Ġstage Ġof Ġthe Ġcampaign Ġ, Ġbeing Ġthe Ġadvance Ġto Ġthe ĠHar i Ġ, ĠMob ia i Ġ, Ġand ĠM ivo ĠRivers Ġ. ĠThe Ġfinal Ġphase Ġof Ġthe Ġbattle Ġcost Ġthe ĠJapanese Ġ106 Ġkilled Ġ, Ġwhile Ġthe ĠAustralians Ġlost Ġ13 Ġkilled Ġand Ġ64 Ġwounded Ġ. Ġ Ġ Ġ= Ġ= ĠAfter math Ġ= Ġ= Ġ Ġ ĠDuring Ġthe Ġcourse Ġof Ġthe Ġfighting Ġaround Ġthe ĠHong or ai Ġ, Ġthe ĠAustralians Ġlost Ġ38 Ġmen Ġkilled Ġand Ġ159 Ġwounded Ġ, Ġwhile Ġthe ĠJapanese Ġlost Ġat Ġleast Ġ275 Ġmen Ġkilled Ġ. ĠFollowing Ġthe Ġbattle Ġ, Ġthe ĠAustralians Ġcontinued Ġtheir Ġadvance Ġtowards ĠBu in Ġat Ġthe Ġsouthern Ġend Ġof Ġthe Ġisland Ġ. ĠThroughout Ġthe Ġremainder Ġof Ġthe Ġmonth Ġand Ġinto ĠJune Ġ, Ġthe Ġ15 th ĠBrigade Ġadvanced Ġalong Ġthe ĠBu in ĠRoad Ġ, Ġcrossing Ġthe ĠHar i Ġon Ġ10 ĠJune Ġ. ĠBeyond Ġthe Ġriver Ġ, Ġthe ĠJapanese Ġresolved Ġto Ġhold Ġthe Ġfood Ġgrowing Ġareas Ġin Ġorder Ġto Ġprotect Ġtheir Ġprecarious Ġfood Ġsupply Ġ, Ġand Ġthey Ġconsequently Ġoccupied Ġa Ġseries Ġof Ġdeep Ġent rench ments Ġ. ĠThese Ġwere Ġsteadily Ġreduced Ġwith Ġairstrikes Ġand Ġartillery Ġ, Ġand Ġthe Ġ15 th ĠBrigade Ġsubsequently Ġcrossed ĠMob ia i ĠRiver Ġbefore Ġbeing Ġrelieved Ġby ĠBrig adier ĠNoel ĠSimpson Ġ' s Ġ29 th ĠBrigade Ġin Ġearly ĠJuly Ġ. Ġ Ġ ĠAs Ġthe Ġ29 th ĠBrigade Ġadvanced Ġtoward Ġthe ĠM ivo ĠRiver Ġ, Ġtorrent ial Ġrain Ġand Ġflooding Ġultimately Ġbrought Ġthe Ġadvance Ġto Ġa Ġhalt Ġ. ĠThe Ġheight Ġof Ġthe Ġriver Ġrose Ġ2 Ġmetres Ġ( Ġ6 Ġ@ . @ Ġ6 Ġft Ġ) Ġ. ĠThe ĠBu in ĠRoad Ġwas Ġreduced Ġ, Ġin Ġthe Ġwords Ġof ĠGavin ĠLong Ġ, Ġ" Ġto Ġa Ġsea Ġof Ġmud Ġ" Ġand Ġmany Ġof Ġthe Ġbridges Ġupon Ġwhich Ġthe ĠAustralian Ġsupply Ġsystem Ġwas Ġdependent Ġwere Ġwashed Ġaway Ġ. ĠThis Ġrendered Ġlarge Ġ@ - @ Ġscale Ġoffensive Ġinfantry Ġoperations Ġimpossible Ġand Ġas Ġthe Ġsituation Ġworsened Ġfor Ġa Ġperiod Ġof Ġtime Ġthe ĠAustralians Ġeven Ġceased Ġpatrolling Ġoperations Ġacross Ġthe