The official Capitulation of Japan was on Sep 2, 1945 (if I'm not mistaken), so there was still fighting in Manchuria and elsewere between Soviet and Japanese Troops in August.
According to my source (Encyclopedia Americana), "On August 14, on the emperor's advice, these [Potsdam] terms were accepted, and hostilities ceased." The formal surrender aboard the Missouri was on September 2, but apparently there was no fighting after August 14.
Not that there was really much fighting with the Russians before that date. According to the same article, "The USSR declared war on Japan on August 8 (effective August 9) and, using a massive force of three strong army groups, invaded Manchuria, Korea, southern Sakhalin, and, later, the Kuril Islands. The Japanese armies in Manchuria, reduced in size and weakened by the need to provide further defense of the homeland, could offer little resistance...."
The Commies were reall brave against defeated enemies.