Officers with Canada Border Services Agency (CBSA) have seized a handgun and an over-capacity magazine at the Ambassador Bridge.
The incident took place on Wednesday, September 27 after a traveller tried to enter the country from the United States.
CBSA says the individual was issued a penalty of $1,500 and was returned to the U.S.
Within as many hours as the Ambassador Bridge incident, a handgun was also seized at the Peace Bridge in Fort Erie, Ont.
The CBSA is reminding people to declare all firearms when entering Canada.
If travellers fail to declare a firearm or are untruthful, the CBSA may seize it, and they may face criminal charges and/or monetary penalties.