NEW: The lake where the girls bicycles were found is being drained, the mayor says NEW: The mayor went searching for the girls himself in his small plane Dogs were used Monday night and may be used again on Tuesday, the FBI says Evansdale, Iowa (CNN) -- Searchers used scent dogs Tuesday as they looked for any sign of two young girls who were last seen on Friday, riding their bikes near a lake in Evansdale, Iowa. The FBI brought two dogs to the area Monday night, and the dogs were used again on Tuesday, FBI spokeswoman Sandy Breault said. When Evansdale Mayor Chad Deutsch heard that two little girls were missing in his town, the first thing he did, he said, was to make sure every city asset that was needed was made available to the county sheriff. The next thing he did was take to the air. A pilot, he took off in his twin-engine plane and flew over his town looking for any sign of Lyric and Elizabeth. "It just makes you sick," said Deutsch, who knows both families. In this town, neighbors know exactly how many people live there -- 4,751 -- and the small community has never suffered through anything like the worrying going on now, the mayor said. Deutsch said Meyers Lake is being drained as part of the effort to find the girls. Their bicycles were found near that lake hours after they were reported missing, and the sheriff's department said on its website that a purse belonging to one of the girls was found not far from the bikes. It might take two to three days to drain the lake to a point where searchers will know if anyone is there, Deutsch said. The search remains a missing persons case, authorities said. No evidence exists right now to suggest this is a crime, Deutsch said, but it is a mystery that has the whole community looking for two of their own. Sitting beside Brousseau during the "AC360" interview was Misty Cook-Morrissey, Lyric's mother. Abben told reporters Monday there was no indication the girls were outside Evansdale, which is located about 12 miles southeast of Cedar Falls. CNN's Martin Savidge, Tristan Smith and Leslie Tripp contributed to this report.