The Mongol invasions are an early example of gunpowder warfare outside of China. One of the most notable technological innovations during the war was the use of explosive bombs.
The bombs are known in Chinese as "thunder crash bombs”.
An illustration of a bomb is depicted in the Japanese Mongol Invasion Scrolls, but it has been shown that the illustration of the projectiles was added to the scrolls in the eighteenth century and should not be considered to be an eyewitness representation of their use.
However, archaeological discoveries recently have confirmed the existence of bombs in the Yuan invasion’s arsenal. Multiple bomb shells were discovered in an underwater shipwreck off the shore of Japan. X-rays by Japanese scientists of the excavated shells show that they contained gunpowder and were also packed with scrap iron.
These trebuchets had a shooting range of around 100 metres, and could use projectiles of around 50kg. During Mongol campaigns against the Jin dynasty, the Mongols used over 5,000 trebuchets, which were very successful in destroying the Jin fortresses.