The Canada Border Services Agency (CBSA) is reporting five separate seizure incidents at the Ambassador Bridge between May 8 and 13.
Over that period, border officers seized four prohibited firearms, ammunition, magazines, brass knuckles, a stun gun, pepper spray, cannabis products and edible gummies.
Those involved were all residents of the United States.
In some cases, travellers were arrested under the Customs Act before being returned to the U.S.
All subjects paid penalties ranging from $500 to $2,000.