Complex sentence: The Muslims are in retreat but the Japanese get bogged down at the Ural Mountains, in the meantime Kuo is killed by a shell which penetrates their bunker and Bai and Iwa are ordered to move with their company south through Tibet to support their Indian allies.
Split into simpler sentences: The Muslims are in retreat but the Japanese get bogged down at the Ural Mountains. In the meantime, Kuo is killed by a shell which penetrates their bunker, Bai and Iwa are then ordered to move with their company south through Tibet to support their Indian allies.