Officers from our proactive Operation Expedite team were patrolling in the town when the suspicious behaviour of the pair led officers to approach them.
The suspects initially ran off from the officers but were detained following a short foot chase.
The pair were searched and two Kinder eggs containing suspected heroin and crack cocaine were found along with a knuckle duster seized from one of the teenagers.
The boys, both from West Yorkshire, are believed to be involved in county lines drug supply into Harrogate.
The 16-year-old was arrested on suspicion of possessing class A drugs with intent to supply, possessing cannabis and possessing an offensive weapon. The 15-year-old was arrested on suspicion of being concerned in the supply of class A drugs.
Both have been released on conditional bail to allow for further enquiries to be carried out.
County lines drug gangs groom and exploit young people into selling drugs on their behalf so they can evade the police.
Please look out for signs that a young person you know might be exploited by drugs dealers and report it to the police on 101. If you don’t want to speak to the police directly, you can pass information anonymously to Crimestoppers on 0800 555 111.
You can also get advice from other organisations such as the NSPCC and the Children’s Society. But if you believe a child is in immediate danger, always call the police on 999.