A series of gruesome photos showed U.S. Marines drinking cobra blood, eating insects and even beheading live chickens as part of a bizarre jungle survival course in Thailand, Daily Mail reported.

The tough Marines were shown by Thai Navy instructors several survival crafts including techniques of hunting down snakes before being given a chance to eat its entrails. Some photos showed several soldiers devouring scorpions and other deadly insects among other feats of the military program.

The 10-day drill held in the Sattahip district of province Chonburi, is an annual training program known as Exercise Cobra Gold. The event co-sponsored by the U.S. and Thailand brings over 13,000 personnel from the U.S., Thailand, Singapore, Japan, Republic of Korea, Indonesia and Malaysia. The point of this program, the publication noted, is to build stronger ties between the U.S. and Asia.

The hard-core military drill goes beyond training soldiers Fear Factor style. Other operations include computer-simulated command-post exercise, field training drills, humanitarian projects, evacuation exercises, including a mock amphibious raid.

According to First Lt. Zachary Duncan, the training program will open eyes to see the jungle environment as plentiful as it is.

The Thais are showing us a lot of tools as well as resources available to us in the jungle that we will be able to exploit to survive in that environment, Duncan said to Dvidshub.net, a military Web site.

According to Army.nil, the exercise program will end on Feb. 17.