Searches have continued over the weekend along the River Tamar for 16 year old Jordan Cobb without success.
Police are asking the public not to carry out their own searching so that resources can be concentrated where they are most needed.
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Aaron Reilly and Joshua Brock, both 19, have been described as "kind" and as men with a "great sense of humour".
Stay cold and unsettled
Staying cold and unsettled