DES MOINES, Iowa — With the trail apparently cold in the search for two missing Iowa girls, the FBI is sending in tracking dogs and local authorities are draining a lake near where the girls' bicycles were found.

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.

What followed was a massive sweep of the area that drew hundreds of volunteers over the weekend. But authorities suspended that effort Monday, saying it had failed to produce significant leads.