Elizabeth Collins and Lyric Cook-Morrissey were last seen Friday at their grandmother's house in Evansdale, a suburb of Waterloo.
Elizabeth Collins, 8, and Lyric Cook-Morrissey, 10, were last seen Friday at their grandmother's house in Evansdale, a suburb of Waterloo. Their bicycles and Elizabeth's purse were found later that day at nearby Meyers Lake, and FBI dogs detected the girls' scent in the area.
FBI spokeswoman Sandy Breault said that if the divers are deployed, they would search the deeper holes of water in the lake, which may be as deep as 20 feet, she said.
Breault also says the FBI's Child Abduction Rapid Deployment team of five or six is on the scene in Iowa. She would not comment on the focus of their investigation.
Family members of the two young girls believe the cousins were abducted after days of investigations appeared to produce no significant leads.
On Monday, authorities began draining the lake, a task that they said could take up to three days.
Officers paddled around the lake in kayaks Tuesday while others walked the shoreline hunting for clues. One officer picked up something that appeared to be a cup and placed it in an evidence bag, but officials did not identify the object to the media.
Breault said the reaction from the dogs indicated a "strong possibility" the girls had been at the lake but that because there were no confirmed sightings there, authorities couldn't be certain.
Chief Deputy Rick Abben of the Black Hawk County Sheriff's Office said the case was still considered a missing persons investigation and that they were draining the lake to rule out the possibility the girls were in the water.