At about 16:40 on 25 December, Japanese troops successfully captured Kuching airfield. The Punjab regiment retreated through the jungle to the Singkawang area. After Singkawang was secured as well on 29 December, the rest of the British and Dutch troops retreated southward further into the jungle, trying to reach Sampit and Pangkalanbun, where a Dutch airfield at Kotawaringin was located. South and central Kalimantan were taken by the Japanese Navy following attacks from east and west. The town of Pontianak was finally occupied by the Imperial Japanese forces on 29 January 1942. After ten weeks in the jungle-covered mountains, Allied troops surrendered on 1 April 1942.