A primary school was reportedly sent into lockdown after two boys were seen carrying an air rifle nearby.
Police were called to Northwall Road in Deal at 11.35am yesterday.
Officers arrested a 15-year-old boy from Deal on suspicion of carrying an air weapon in a public place, and seized the item.
Sandown Primary School - in the same road - is said to have gone into lockdown and closed all of its blinds, although head teacher Kate Luxford has refused to comment.
A police spokesman said: "No injuries were reported.
"The boy remains in police custody pending further enquiries."