Two recent river otter attacks on swimmers at Lake Tahoe have prompted wildlife officials to warn people to keep their distance from the animals.

One attack occurred at Hidden Beach, where a swimmer was bitten and scratched repeatedly and required 38 stitches and rabies treatment.

Another swimmer was attacked at Pope Beach and suffered multiple bites and scratches before receiving medical care.

Officials say river otter attacks on humans are extremely rare and may happen when the animals feel threatened or are protecting their young, South Tahoe Now has reported.

Authorities are urging visitors not to approach or feed otters and to seek immediate medical attention if they are bitten or scratched.