(CBS4) – A piece of clothing belonging to a missing 3-year-old Colorado boy with autism was found along with a phone that he used in a river in Eagle County. Search teams have been combing through areas around Eagle, Gypsum and Dotsero since Sebastian Castro went missing on Friday, and those efforts will be centered around the river on Monday.

Sebastian Castro

Sebastian Castro (credit: Eagle)

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The teams include volunteers, mountain rescuers, dog teams and drones, and the discovery of the clothing and phone was made sometime on Sunday.

Sebastian was reported missing after 9 p.m. from the Eagle Villas apartments. A boy matching his description was seen at the playground on the property.

Sebastian Castro

(credit: Eagle)

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His family says he responds to children’s songs, animal noise and colorful items. They add he may not be comfortable with adults he does not know.

Sebastian Castro

(credit: Eagle)

Officials ask the public to not fly private drones in the area and leave water searches to professionals.

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Volunteers have been asked to sign up online before helping crews.