An evening of inner tubing turned perilous for three Montana women when they were attacked by an otter.

The women were floating along the Jefferson River on Wednesday around 8:15 p.m. when they observed one or two otters, the Montana Fish, Wildlife and Parks (FWP) said in a news release Thursday.

At least one otter attacked the women, who called 911 when they were able to get out of the water.

All three women received treatment for their injuries. One of the women had "more serious" injuries and was flown to a hospital via helicopter, according to the release.

Montana FWP has posted signs at various recreational fishing sites advising people of otter activity in the area. This is the only action the agency plans to take for now, the release said.

"While attacks from otters are rare, otters can be protective of themselves and their young, especially at close distances," Montana FWP said. "They give birth to their young in April and can later be seen with their young in the water during the summer. They may also be protective of food resources, especially when those resources are scarce."

People should "give all wildlife plenty of space" and keep a wide distance to avoid dangerous encounters and reduce stress on the animals, according to the news release.

"If you are attacked by an otter, fight back, get away and out of the water, and seek medical attention," Montana FWP added.