Within days of gaining passage through Thailand, Japanese forces were probing southern Burma. On 12 December, 2nd Battalion, 143rd Infantry Regiment, 55th Division crossed the Kra Isthmus. The Regimental Commander, Colonel Uno, and one rifle company led the way, and seized the abandoned airstrip at Victoria Point on the 14th. By Christmas, a company-sized advance party under Lieutenant Furutuki had travelled by sea and taken the police post at Bokpyin, a coastal settlement roughly 150 kilometres to the north. A counterattack on Boxing Day was thrown back, with significant casualties to both sides. The same day, the 2nd Battalion of the Burma Rifles (stationed in Mergui) dispatched reinforcements southward. The rifle company arrived in Bokpyin two days later. Supported by a gunboat and a 3-inch mortar, C Company put in a spirited attack.