Updated

Hundreds of volunteers are searching around an Iowa lake for two girls who disappeared from the area, authorities say.

Cousins Lyric Cook, 10, and Elizabeth Collins, 8, were last seen shortly after noon on Friday in downtown Evansdale. Their bikes were located along a trail on the southeast corner of Meyers Lake. Black Hawk County investigators say they have found no other traces of the girls.

Authorities say about 40 percent of the lake has been searched, the Waterloo-Cedar Falls Courier reports. Investigators also are contacting registered sex offenders, the girls' family and friends of the family for possible clues.

Misty Cook Morrissey, Lyric’s mother, believes the cousins were abducted.

She told the paper Saturday that it is out of character for her daughter to wander too far from home. The girl often stays at her cousin Elizabeth’s home while her mother works.

Evansdale police and fire chief Kent Smock say authorities still view it as a missing-persons case, but he isn't ruling out the possibility that the girls were abducted.

Click for more from the Waterloo-Cedar Falls Courier.

The Associated Press contributed to this report.