Authorities have launched a massive search Thursday in attempt to locate a developmentally disabled teenager who has been missing since last weekend.

Annoldo Lopez Soto says his 16-year-old brother, Francisco Noa Lopez Soto, was last seen early Sunday morning near a Brewster home that is frequented by Guatemalan immigrants.

More than 100 officers from the Putnam County Sherriff's Office, state police and the Metropolitan Transportation Authority have been scouring a heavily wooded area in search of the teen, who has the emotional maturity of a child.

"We don't have any indication of foul play, but we certainly are worried," says Putnam County Sheriff Don Smith.