OAKDALE — Two teenage girls found shot to death on a central California riverbank likely took their own lives, authorities said.

A fisherman discovered the bodies Saturday morning along the Stanislaus River in Oakdale, the Sacramento Bee reported.

Both victims had suffered small caliber gunshot wounds, said Oakdale Police Chief Scott Heller.

“The preliminary investigation indicates the case is a tragic double suicide involving two juvenile females, ages 15 and 17,” Heller said Saturday afternoon.

Heller said both girls were from Oakdale. “We are still investigating their relationship,” he said.