DES MOINES, Iowa – Authorities began draining an Iowa lake Monday in the search for two missing girls whose bicycles were found nearby, but they suspended a massive sweep of the area that drew hundreds of volunteers over the weekend because the effort failed to produce significant leads.

Elizabeth Collins, 8, and her cousin, Lyric Cook-Morrissey, 10, were last reported seen Friday afternoon leaving their grandmother's house. Their bicycles and Elizabeth's purse were found later that day near a bike trail at the edge of Meyers Lake in the northeast Iowa city of Evansdale.

Black Hawk County Chief Deputy Rick Abben said the draining of the nearly 5-acre lake began Monday and 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.