A frantic search has been launched after a three-year-old non-verbal boy reportedly fell from a third-floor window before vanishing.

Autistic Braylen Noble?has been missing since Friday, with the FBI called in to assist with the search.

His mum Dajnae Cox told police she believes Braylen had fallen from the window of an apartment in Gibralter Heights, Ohio, before disappearing.

Officers and groups of volunteers scoured the surrounding area, but have found no trace of the little boy, who was wearing a Mickey Mouse top.

The little boy's grandfather Jeffrey Holloway described Braylen as “very strong, joyful”.

The FBI has joined the search for the missing toddler

He told a vigil, the Toledo Blade reports : “I feel that if we get together and pray maybe somebody will break loose and return my grandson or give us some answers."

Dajnae initially called for people to help search for her son on Facebook, but deleted her profile after being targeted by cruel trolls, according to reports.

Officers searching a nearby river after Braylen's disappearance
A reward has been offered for information that can help find Braylen

Toledo Fire and Rescue Department spokesman Sterling Rahe said: "We've searched probably a quarter mile in each area from this area, maybe even beyond that, with nothing found.?

"It's been searched multiple times. All of the adjacent buildings have been searched."

Officials have warned people about spreading rumours about the case on social media.

Lt. Kellie Lenhardt said: "False social media rumors, we cannot say it enough, please verify the information you are reading before you share it and cause more concern among people."

The FBI is now offering a $5,000 reward to anyone who can help trace Braylen.