Japanese conquest of Burma main attack westward from Rahaeng in Thailand across the Kawkareik Pass. The 16th Indian Infantry Brigade of the 17th Indian Division guarding this approach retreated hastily westward. The Japanese division advanced to Moulmein at the mouth of the Salween River which was garrisoned by the 2nd Burma Infantry Brigade. The position was almost impossible to defend, and had the River Salween, almost wide, behind it. The 2nd Burma Brigade was squeezed into a progressively tighter perimeter, and eventually retreated over the river by ferry on 31 January after abandoning a large amount of supplies and equipment. Part of the force
Suárez River horse drowned in the river when it experienced sudden flooding. The original name in Chibcha, given by the Guane was "Saravita", meaning "departs from here". The Suárez River is long and its drainage basin extends over , of which in Santander. It is sourced by Lake Fúquene in Boyacá at an altitude of and forms together with the Chicamocha River the Sogamoso River in Santander at an altitude of . The river starts on the Altiplano Cundiboyacense where it forms the boundary between Cundinamarca and Boyacá and for a major part of its course downstream it is the natural boundary