Hundreds of people have gathered in Montgomery to show their support for the missing teenager James Corfield and his family.
Wearing blue in a show of solidarity, the large group met outside the town hall at 11am.
Members of the public have been asked to stay away from the search area due to the specialist nature of the search and for their own safety.
Emergency services are continuing their search along the river with the use of Mid and West Wales Fire and Rescue Service’s drone.
James was last seen at the White Horse public house, Builth Wells, at around midnight on Monday.
He is described as being 6ft 2 inches tall, of slim build, with short brown hair.
He was last seen wearing a blue Abercrombie and Fitch shirt and jeans.
James was reported missing shortly before 2pm on Tuesday, after failing to meet his family at the Royal Welsh Show, where he had been camping with friends.