A Christian teen has been attacked by a bear while on retreat in the Rockies in Colorado.

The youth, named as Dylan and believed to be around 18 years old, was dragged from the Christian camp  by the black bear and bitten twice in the head at Glacier View Ranch, near Boulder.

The attack took place in the early hours of the morning. The bear was chased off by other campers. The youth was not seriously injured, and has been discharged from hospital, Denver7 reported.

Glacier View Ranch describes itself on its website as a high-altitude place 'to experience God as Creator, Re-Creator, and Friend'.

Rangers are now hunting the bear. Normally, black bears are not dangerous but they can become so when hungry.

'The crunching noise, I guess, was the teeth scraping against the skull as it dug in,' Dylan told Denver7. 'It grabbed me like this and pulled me. Then it bit the back of my head and drug me.'

Dylan is an expert in wilderness survival and was teaching it to youngsters at the camp.

He said he was not afraid.

'You just have to be aware and respect the animals.'

In the area around Colorado's Durango city, two bears were recently shot by householders after they entered their homes, and two more have been killed by Wildlife Services.