The Official Historical Records of Dai Viet (Dai Viet Su Ky Toan Thu - 大越史記全書) described the killing methods of Ming troops as follows:

“…輔所至多行殺戮，或積屍爲山，或抽腸繫樹，或煎肉取䐧，或炮烙爲戲，至有剖胎為二馘以應令者...”

English translation:

“Whenever General Zhang Fu (張輔) mobilized his troops, they massacred lots of people. Sometimes they cut the bowel out of the victim’s body, tied it to the tree, or make the fried meat ! Some of these soldiers even disemboweled the body of a (female) pregnant victim and chop off the head of her child !”

Vietnamese version:

“Phụ đi đến đâu, giết chóc rất nhiều, có nơi thây chất thành núi, có chỗ moi ruột quấn vào cây, hoặc rán thịt lấy mỡ, hoặc nướng đốt làm trò, thậm chí có đưá mổ bụng lấy thai, cắt lấy hai cái tai để nộp theo lệnh”.

On the other hand, the CULTURAL GENOCIDE was escalated rapidly. Hundreds of precious books written by Vietnamese people were taken away from Royal Court as well as from private libraries, to be burnt at all !

Thanks to the works of Vietnamese
during 1930s, the previous book named “越嶠書” (Việt Kiệu Thư) written by the author Li Wenfeng (李文鳳) was finally discovered and brought to the light. Inside this old book there was an official decree from Ming Emperor Yongle announced that:
“…兵 入 。除 釋 道 經 板 經 文 不 燬 。外 一 切 書 板 文 字 以 至 俚 俗 童 蒙 所 習 。如 上 大 人 丘 乙 已 之 類 。片 紙 隻 字 悉 皆 燬 之 。其 境 內 中 國 所 立 碑 刻 則 存 之 。 但 是 安 南 所 立 者 悉 壞 之 。 一 字 不 存…”

English translation:

“Whenever your army enter Annam, except Buddhist and Taoist text, all written and printed materials of Annam must be burnt. The stelae erected by China during the previous time have to be protected carefully. On the contrary, those stelae erected by Annamese must be completely annihilated, not a single character left”.