"von arnim" and "thiele" were the first to refuel from the single tanker that had made it safely to narvik and later moved to the ballangenfjord, a southern arm of the ofotfjord, closer to the entrance. shortly before dawn on 10 april, the five destroyers of the british 2nd destroyer flotilla surprised the five german destroyers in narvik harbor. they torpedoed two destroyers and badly damaged the other three while suffering only minor damage themselves. as they were beginning to withdraw they encountered the three destroyers of the 4th flotilla which had been alerted in the herjansfjord when the british began their attack. the germans opened fire first, but the gunnery for both sides was not effective due to the mist and the smoke screen laid by the british as they retreated down the ofotfjord. the german ships had to turn away to avoid a salvo of three torpedoes fired by one of the destroyers in narvik, but "von arnim" and "thiele" had also been alerted and were coming up to engage the british.