Two teenagers have been severely injured in shark attacks off the coast of North Carolina.

A female victim lost part of her arm and could lose her left leg after the attack off Oak Island, near Wilmington, officials said.

Oak Island mayor Betty Wallace said the victim is not from the area but was visiting family.

Ms Wallace did not have further information on the girl's prospects for recovery.

Brunswick County emergency dispatchers received the call and several agencies responded to the scene including Oak Island Police and the Air Link Helicopter.

The second incident was reported shortly afterwards. A 16-year-old boy lost an arm and was airlifted to hospital.

The Oak Island town manager sent a team to get everyone out of the water, the mayor said, adding that the Brunswick County Sheriff's office was sending a helicopter up and down the coast to patrol.

Steve Bouser and his wife were at the beach at the beginning of a week's holiday when he said people began yelling: "Come in! Get out of the water! Get out of the water!"

"I saw someone carry this girl (out of the water) and people were swarming around and trying to help. It was quite terrible."

He said there was a lot of blood and people were trying to apply makeshift tourniquets to stop the bleeding. He added that people were asking her questions to try to keep her conscious. It was "quite nightmarish", he said.

"It was so much like a scene from Jaws," his wife Brenda added.