A woman has died after an alligator bit off one of her arms in Florida.

The 31-year-old was hiking with her boyfriend and best friend near Orlando at the time of the attack on Sunday.

They had waded into the Econlockhatchee River to cool off - and were kneeling in 3ft-deep water.

Her boyfriend was still "trying to get her arms away from the alligator's mouth" when he rang 911 for help, local officials said.

Screams and crying could be heard in a recording of that call, obtained by Sky's US partner NBC News.

The operator was told that "both her arms, both her arms are off" - with a woman on the phone saying that one of them was "hanging by a thread".

When the emergency dispatcher asked where the other arm was, she replied: "Gone."

The victim died before rescue workers could get her to a hospital, and she is yet to be publicly identified as officials attempt to contact her family.

Two alligators - one 12ft long and the other 13ft - were trapped at the scene and have undergone DNA testing to establish which one attacked the woman.

Lt Grant Eller said it was unclear what caused the attack, but "alligators are territorial at this time of year" because it is the end of mating season.

Serious injuries caused by alligators are rare in Florida, but three attacks have been reported in the past seven days.