The Tauran Incident, was fought between forces of the Soviet Union, Mongolia, Japan and Manchukuo, during the Soviet–Japanese border conflicts, for control of the Mongolian border village of Tauran.
Timeline.
On 11 March, an army of less than 100 Mongolian soldiers with six Soviet advisors invaded the disputed village of Tauran, where they defeated the Manchurian defenders. Later that same day the Imperial Japanese Army with some Manchurian volunteers launched a massive attack to retake the village. The Japanese forces consisted of ten armored vehicles and dozens of warplanes, which bombed the village overnight. The next morning the Japanese launched their ground assault with a force of more than 400 soldiers and a few tanks. The Mongolians were slaughtered and barely did any damage to the Japanese as they were forced to retreat. 
Aftermath.
A quarter of their initial force was killed along with two officers and their commander, Feodor Sokolow. Three Soviet advisors were also killed, creating tensions between both nations.