Police surrounded a house in a residential neighbourhood on Seal Way just south of Peardonville Road in the Clearbrook area Thursday morning around 10:30 a.m.
At least six police units and as many officers arrived on the scene responding to a report of a weapon.
Four people were taken into custody and later released. The house was expected to be held by police for the rest of the day.
One resident of the area said police were conducting surveillance of the cul-de-sac where the house is located a week ago.
"We were in our back yard when they came by and told us not to be worried if we saw them," Albert Kroeker told The News.
Another resident, who asked not to be identified, said the people in the house were "not good neighbours" but the house has not been raided previously, as far as they knew.
A third resident said the house in question was a rental property.