A University of Texas graduate student, Andrew Oberle, fought for his life in South Africa as two chimpanzees pounced on him at a reserve where he was studying their behavior. The primates dragged the injured man along the ground for more than a mile as he tried to break free.

The chimpanzees named Mickey and Amadeus grabbed the 26-year-old by his feet and dragged him under a fence and into their enclosure at the Jane Goodall Institute's Chimpanzee Eden near Nelspruit, South Africa, the Daily Mail reported.

According to eyewitnesses, two chimpanzees grabbed the man by his feet and pulled him under the perimeter fence and into the enclosure, said Jeffrey Wicks, a representative of emergency service Netcare 911, Agence France-Presse reported.

As paramedics arrived on the scene to help Oberle, they could not approach the enclosure. The animals were aggressive, and they were difficult to approach. They had to wait for armed guards before they extracted the victim.

When we found him, he was in a fetal position underneath a lapa (a roofed, open-walled structure) with massive injuries, lacerations, abrasions, partial amputation from his head to toe, Lloyd Krause, a representative of the ER24 emergency service, was quoted as saying by AFP. He lost an ear, he lost a number of fingers and toes, he's got very deep wounds, he's got total removal of skin and muscle off his one leg and his one arm, fractures all over the place.

Oberle is now in an intensive-care unit at Mediclinic Nelspruit hospital, where he underwent emergency surgery.

He has multiple injuries and is in a critical condition. He is under close observation in the intensive-care unit and the next 24 hours are crucial, hospital representative Liza Pillay told AFP.

Oberle was reportedly experimenting with different food types. He wrote on his Facebook page that the mustard was a big hit.

David Oosthuizen, the executive director of the Jane Goodall Institute, commented on the situation. This is a terrible tragedy that should never happen. All our thoughts and prayers are with this young man and his family, he said, reported the Daily Mail. Any interaction between humans and wild animals can be dangerous, as wild animals are often very strong and can act aggressively if approached or if they feel threatened. Additionally, the chimpanzees at Chimp Eden have suffered horrible injuries and abuse from humans and therefore have to be treated with caution.