A massive search operation is under way in and around a Suffolk village for a missing three-year-old boy with autism, supported by hundreds of volunteers.

Suffolk police have said the hunt for Noah Woods remains a missing persons investigation with no indication anything sinister has happened.

Noah, who is autistic, non-verbal and partially deaf, went missing after a visit to a play area in the village of Brantham on Tuesday afternoon when he became separated from a relative. Police have said Noah will not respond to his name if called.

In an update on Wednesday, Supt Tom Pearse from Suffolk police said: “This is being treated as a missing person investigation at this stage and there is nothing to indicate anything sinister or any element of criminality has taken place although we keep an open mind as to the circumstances.”

The force released new CCTV stills and footage of the little boy in the play area in Merriam Close just before he vanished.

It is thought that he ran down an alleyway beside the playground towards a nearby new-build housing estate.

The surrounding area includes woods and a pond and is near the River Stour and a railway.

Noah is white with curly ginger hair and was wearing a white T-shirt featuring the TV character Bluey, shorts, and black Vans trainers with a white stripe.

On Wednesday, volunteers could be seen in hi-vis jackets helping to search the area, with efforts being coordinated from the village hall and a leisure centre.

They are part of a massive search operation led by police, fire, coastguard and search and rescue teams, with sniffer dogs being used and a helicopter flying overhead.

As well as the ground search, officers are looking at CCTV and other available video footage, going door to door and carrying out aerial and thermal imaging searches.

Noah’s father posted on social media asking volunteers to widen their search beyond the village where possible.

He wrote: “I cannot go another night knowing he’s out there alone, please don’t give up on him guys. He is out there somewhere and I appreciate every single one of you.”

In the update from police on Wednesday, Pearse urged volunteers to report to the coordination centre and to avoid the railway and open water, which need specialist searching.

He said: “It has now been around 24 hours since Noah was reported as missing to us and we are doing everything we can to find him.

“We are extremely grateful for the support shown by the public. If you are helping please report into the coordination centre to ensure the search continues to be done in a systematic and coordinated fashion.

“This will ensure we can carefully plan and take account of people supporting the search.

“We politely ask people to avoid open waters and railways – these are areas that require specialist and professional expertise. We also ask that personal drones are not used as these can interfere with specialist search equipment.

“There may also be times when officers may need to restrict access to certain areas or move away from search locations.

“Please do not be offended if this happens; it is necessary to allow us to carry out our inquiries and search activity as effectively as possible.”

Advice from Brantham parish council to volunteers included: “You are looking for a frightened three-year-old. Think about slight movements in your peripheral [vision], high and low, tiny small spaces use all your senses whilst searching.”

They have been told not to grab or approach Noah if they find him, but instead to call police on 999 immediately and give their exact location using the What3Words app.

Anyone with private CCTV or doorbell cameras in the village, or who was driving through the area with a dashcam is asked to review the footage from 3pm on Tuesday afternoon onwards for any possible sightings of Noah.