Updated

Authorities in Evansdale, Iowa,  are draining an Iowa lake as they continue their search Monday for two missing cousins who disappeared and whose bicycles were found nearby. Authorities called off all volunteer search efforts after hundreds turned out to help over the weekend.

More than 350 volunteers helped search the area around Meyers Lake for 8-year-old Elizabeth Collins and her 10-year-old cousin, Lyric Cook-Morrissey. The cousins were last seen shortly after noon Friday.

Their bikes were found near Meyers Lake a few hours after they were reported missing. Investigators found Collins’ purse 25 feet away from her bike, the Des Moines Register reports, but no other belongings.

Black Hawk County Chief Deputy Rick Abben says the draining of the nearly 5-acre lake began Monday and it could take up to three days. Officials believe it will go faster due to the low level of the lake and the Cedar River into which it drains.

Authorities had been dragging the lake and have been interviewing family, friends and registered sex offenders who live in the Evansdale area, but have no firm leads. Police are now searching door-to-door for leads.

“There’s nothing to indicate anything at this time other than that we have two missing girls,” Black Hawk County Sheriff’s Deputy Rick Abben told the Des Moines Register.

Authorities told the newspaper that they believe the girls are not in the lake, but since no suspects or vehicles have been identified in connection to their disappearance, it’s still being treated as a missing persons case.

The Associated Press contributed to this report.

Click for more from the Des Moines Register.