The landings began at 04 : 30 on 5 May , with 5 Commando landing at Courrier Bay and the three infantry brigades and ' B ' Squadron landing at Ambararata Bay . The objective of the infantry brigades and their armoured support was to take control of Antsirane and a nearby town , but although the infantry landed successfully , ' B ' Squadron had more trouble ; the area of beach designated for its landing craft was blocked for several hours after a Tetrarch came loose from a landing craft and became stuck in the sand . The infantry brigades advanced toward Antsirane without the squadron , but eventually two Valentines and a single Tetrarch were dispatched in support , catching up with the lead elements of the infantry near the town of Anamakia . Here the invasion force encountered the first French defences , consisting of camouflaged trenches and pillboxes dug in along a ridge . The tanks attempted to breach them , but the rocky ground made manoeuvring difficult and they could not close with the pillboxes and trenches ; they engaged a number of targets with 2 pounder and machine @-@ gun fire , but the line had to be cleared by an infantry assault later in the day . The tanks were ordered to outflank the defences and advance further into the island , and they were soon joined by two other Tetrarchs dispatched from the beaches ; the small force continued to advance until it encountered the Vichy French main line of defence . This had been built prior to the First World War and included camouflaged pillboxes , machine @-@ gun nests and dug @-@ in 75 mm artillery pieces ; the latter , although not specifically designed for an anti @-@ tank role , could penetrate the armour of both the Tetrarchs and the Valentines . The two Valentines advanced first but were knocked out by artillery fire , and two Tetrarchs that were moving behind them suffered the same fate ; the third Tetrarch retreated in order to report on the French resistance , machine gunning a motorcycle combination and a truck it encountered on the way back .