On August 5th, 1944, more than a thousand Japanese prisoners of war broke out of the Cowra POW camp in eastern Australia. It was the biggest prison break of World War II.
The Cowra camp contained Japanese, Italian, and Korean POWs that had been captured in action in the Pacific and Middle East (there were also a few Indonesian civilians). The Japanese officers were separated from the lower ranks, and it was men from the lower ranks who staged the breakout.
The sequence of events here is a bit strange: the Australians heard a rumour that a mass escape was being planned, so they told the Japanese prisoners that they were going to be moved to another camp. The next day, a bugle sounded, and the escape began.
(Incidentally, the bugle was sounded by the very first Japanese soldier to be captured in WWII, Hajime Toyoshima. He was a Zero pilot in the bombing of Darwin and was captured when his plane crash-landed.)
The POWs were armed with knives, baseball bats, and garottes; the Australians had machine guns. You can imagine the bloodbath: 231 Japanese soldiers died (including Toyoshima), and more than three hundred escaped. It didn’t stick, though: all of the remaining escapees were caught later.