However, the Regia Aeronautica continued its raids and the fall of Crete to combined air and sea landings on 1 June led to fears that Malta would be next, so further reinforcements including 32nd LAA Rgt were sent out in Operation Substance. The convoy consisted of one troopship and six storeships, with a large escort of warships. It passed through the Straits of Gibraltar on 20 July; unfortunately the troopship ran aground, so only the troops embarked on the storeships and warships could continue. This included 32nd LAA Rgt and 58 new Bofors guns, of which 10 were mounted on the merchant ships for AA defence. Air attacks on the convoy began on the morning of 23 July, but although some of the escorting warships were sunk or damaged the convoy continued. During the night there was an attack by Italian motor torpedo boats, which hit one of the merchant ships. However, the troops aboard were transferred to escort vessels and convoy, including the damaged ship, reached Grand Harbour on the morning of 24 July. The men left at Gibraltar, or aboard the damaged escorts, were brought to the island aboard fast warships on 31 July.