A man eagerly poses with the carcasses of the two endangered monkeys.

In the images posted online Monday, the men brutally tortured the animals, which are thought to be douc langurs (Pygathrix), an endangered species, before eviscerating and barbecuing them.

Within hours of the Internet posting, animal rights advocates and others had criticized the men and called them inhuman in more than 1,000 comments.

Deputy Director of Department of Forest Management Trieu Van Luc told Tuoi Tre on Wednesday he discovered the information through media outlets.

“This is a serious case. I’m currently on a business trip in Quang Binh province. I will be present in Quang Nam on Thursday (today) to work with the Department of Forest Department regarding this case,” Luc said.

Tran The Lien, chief of Nature Conservation and Director of the Nature Conservation Department under the Directorate of Forests, also voiced his outrage at the brutal killing.

“Their acts are unacceptable and should be strongly condemned. They can face criminal charges regardless of who they are – soldiers or civilians,” he said.

Lien added killing douc langurs, which are listed in Vietnam’s Red Book of endangered and threatened species, is a serious offence.

That same day Phan Tuan – chief of Quang Nam Department of Forest Management – told Tuoi Tre that he has asked police to launch probes into the case.

“If the killing occurred in Quang Nam, we will ask police to file charges against the involved people,” Tuan claimed.