Colombian Kids Who Survived Fatal Plane Crash Are Now Kidnapping, Ransom Targets

The 4 kids who survived a fatal plane crash in Colombia and then somehow made it out alive after 40 terrifying days in the jungle are not out of danger ... because they are now prime targets for kidnapping.

TMZ has prepared a documentary on their incredible survival story that airs tonight on FOX at 8 PM ET, and the doc ends with the question -- Where do they go from here? Fact is, the kids -- ages 13, 9, 4 and 11 months at the time of the crash -- are now national celebrities.

People on the ground in Colombia who know the lay of the land tell us, ransom is currency in their country, and insurgents frequently target high-profile people for kidnapping.

As the kids recover physically and emotionally, government officials are trying to figure out who should care for them, and safety is a big factor.

You'd think their father would become the caregiver, but a bitter custody battle has exploded between the dad and the maternal grandparents. The grandparents claim the dad, Manuel Ranoque, was physically abusive toward the kids' mom, even striking her with a machete. The father tells TMZ he has never abused his late wife or the kids.