Authorities searching for two missing Iowa cousins have information that leads them to believe both girls are still alive, an FBI spokeswoman said Saturday.

FBI spokeswoman Sandy Breault said authorities "feel strongly" that Lyric Cook-Morrissey, 10, and Elizabeth Collins, 8, have not been killed.

She refused to say what led authorities to that conclusion, but urged anyone with information about their disappearance to contact law enforcement.

The announcement came a day after authorities finished searching Meyers Lake in the northeast Iowa town of Evansdale, which is near a path where the girls' bikes were found. The girls vanished July 13.

They now say they believe the girls were abducted, but that searching and draining part of a lake was part of a thorough investigation.

The lake is close to Interstate 380, just outside of Waterloo, which is about 120 miles northeast of Des Moines.

Breault said investigators are interviewing multiple "persons of interest" in the case, whom she declined to identify.

She said authorities are still receiving tips on the case, mostly from within the area.

Authorities have said they are watching Lyric's father, Daniel Morrisey, although they have not named him as a suspect.

Morrisey, 36, has a long criminal history and has stopped cooperating with police.