Cooke led his small squadron past Corregidor on 15 January and turned south . Four days later in a storm one of the gunboats broke its tow line and was never seen again , lost with its twelve crew . The frigates subsequently scouted Mindanao before reaching Zamboanga on 22 January . There Cooke raised Spanish colours in an attempt to deceive the authorities into supplying food and water to his squadron but Sybille grounded on a sandbank at the entrance to the port which raised the suspicions of a guardboat sent by the governor of Zamboanga , Raymundo Español . The captain of the Spanish boat asked the British ships the names of their captains , and on receiving no answer but a volley of rifle fire , he put the town on alert . With the defenders forewarned , Cooke abandoned his ruse and after refloating Sybille the following morning , ordered a bombardment of the fort protecting the harbour . This had little effect , though later the Spanish recovered at least 450 cannonballs from different calibers , and Malcolm then attempted an amphibious landing in order to storm the landward side of the fort . The boats came under heavy fire , one smashed by a cannonball , killing two and wounding four . Another boat grounded on a sandbar and became stuck ; so with his force in disarray , as 250 villagers armed with lances ambushed and drove the British from the beach , Malcolm called off the operation . After exchanging shot for an hour both frigates cut their anchor cables and retreated out of range , with two dead and one wounded on Sybille and eight wounded on Fox , in addition to those lost in the boats . The defenders lost a single man killed and 4 wounded .