Wildlife trappers in Washington state searched on Friday for a river otter blamed for a rare attack on humans that sent a boy and his grandmother to the hospital, wildlife experts said.
The boy was swimming in the Pilchuck River in Snohomish County, about 36 miles (57 km) northeast of Seattle, when the otter repeatedly bit and scratched him, said Captain Alan Myers of the Washington Department of Fish and Wildlife.
The boy's grandmother tried to intervene and the otter also attacked her, scratching and badly injuring her eye, he said.
Both were hospitalized after the incident on Thursday and are expected to make full recoveries.
"All indications are that this was unprovoked," Myers said. "Those animals do not have a tendency for aggression."
River otters are semiaquatic animals that generally live along river banks and hunt for fish underwater. They are able to hold their breath for about eight minutes. An adult can weigh between 11 and 30 pounds (5 to 14 kg).
Trappers were searching for the otter, who will likely be euthanized unless it is a female with pups.
"It's not yet known if this was a female trying to protect her pups, or an aggressive male protecting territory," Myers said. "In the case of a female with pups, we will try to relocate the animal to a remote location," he added.
Myers also warned people visiting the area to be cautious.
"In my 15 years with the department, I've never had an experience with an aggressive otter," he said.
(Reporting by Victoria Cavaliere in Seattle; Editing by Daniel Wallis and James Dalgleish)