Homes were evacuated when a suspected explosive device was found.
The item, understood to be a Second World War mortar was discovered by teens at a former caravan park in Division Lane, Marton.
Bomb Disposal experts from the Army were called in and a 200m exclusion zone was set up around the site.
Seven houses were evacuated as a result with residents sent to South Shore Cricket Club.
The device – which The Gazette understands was discovered by teens who had gained access to the site - was taken to the beach where a controlled explosion was carried out.
Residents were allowed to return to their homes in the early hours of Friday.