At the same time as the landing operation at Aparri, the Kanno Detachment disembarked at Vigan faced no opposition from American forces; however, reports of the landing was conveyed to
General MacArthur’s headquarters in Manila by a reconnaissance
Curtiss P-40 Warhawk, and the
Far East Air Force launched a response consisting of five
Boeing B-17 Flying Fortresses and escorting P-40 and
Seversky P-35 fighters of the
34th Pursuit Squadron. The initial detachment from the Kanno Detachment quickly secured the city of Vigan by 1030 in the morning; however as at Aparri, the Japanese landing operation was hampered by heavy seas and strong winds. The American aircraft attacked the Japanese fleet with bombs and strafing attacks, and one of the Japanese transports, the
Oigawa Maru was forced to beach to prevent sinking. A second transport, the
Takao Maru was also beached in a subsequent attack, and one minesweeper, was sunk. The Japanese also had casualties on the destroyer
Murasame and light cruiser
Naka (which suffered 3 crewmen killed) and 30 men in the transport
Hawaii Maru were wounded, despite air cover by eighteen fighters of the IJAAF 24th Fighter Regiment. Due to continuing bad weather, the Vigan Landing Force was shifted four miles to the south, where it was finally able to land the remainder of the Kanno Detachment on 11 December. A small detachment was quickly sent north to capture
Laoag, capital of
Ilocos Norte Province, fifty miles away, along with its airfield. With the Americans on the run, Homma decided to leave only a small garrison at Vigan, and to move the bulk of his combat forces to south to assist the Japanese landing force at
Lingayen Gulf. By 1300 on 20 December the Tanaka Detachment from Aparri and Kanno Detachments had joined together as a single regiment, and marched out of Vigan south along coastal Route 3. Repairing destroyed bridges along the way, the Japanese reached the town of reached
Bacnotan by the evening of 21 December. Bacnotan was defended by elements of the Philippine 11th Division, but the Japanese made a flanking movement to the east and forced part of the defenders back, while cutting off reinforcements from the mountains to the east. The Japanese reached
San Fernando, La Union, on the morning of the 22 December, only a few hours after the main elements of the
IJA 14th Army began the
Japanese invasion of Lingayen Gulf, just to the south. == Consequences==