KALISPELL, Mont. -

State wildlife officials are investigating after two adult otters attacked a boy who was swimming at Lake of the Woods east of Kalispell.

Fish, Wildlife and Parks investigator Brian Sommers says the otters bit the boy on the legs several times on Monday. He was treated at a Polson clinic and released.

FWP personnel searched the site of the attack on Monday night, but did not find the otters. They will continue to monitor the area and have warned area residents about the attack.