After the first week the Italian aviation started to attack: on 17 June some Italian IMAM Ro.37 aircraft undertook a reconnaissance of Djibouti, noting five or six warships in the port and about twenty aircraft at a nearby aerodrome. On 21 June eleven Caproni Ca.133s bombed Djibouti in the largest raid of the colony's brief war. Anti-aircraft fire was intense and two Italian aircraft failed to return, but fires and explosions were seen in Djibouti.