A seventh suspicious package has been found at a Toronto costume store, capping a strange Halloween weekend in which the business had to be closed on two separate occasions because of unwelcome deliveries.

The latest package at the Amazing Party and Costume store, located off the Gardiner Expressway just west of Islington Avenue, was found Tuesday afternoon. Toronto police confirmed officers were on the scene investigating.

It is not immediately clear what the package is or when it was found.

The store was forced to close Tuesday after police discovered a suspicious package on Monday evening and two more on Tuesday morning.

Two fire trucks wait ouside the Amazing Party and Costume in Toronto. (Natalie Kalata/CBC)

The latest packages bring the total to seven, as three previous packages were found at the store over the Halloween weekend.

Investigators have confirmed that at least two packages contained "sophisticated" explosive devices — a mix of incendiary and explosive devices — that could cause death or serious damage.

A bomb disposal squad examined the building earlier Tuesday morning.

"They're the real deal," said Toronto police Insp. Gerry Cashman. "They can cause serious bodily harm or death and or serious property damage because they can ignite and they can cause a fire."

Cashman also highlighted the challenges of sifting through the costume-packed warehouse, noting it is "very difficult to get through all that inventory."

Officers with dogs and bomb-detecting robots located the devices.

The costume store and two neighbouring buildings were evacuated and, after a brief opening on Monday, remain closed Tuesday.

Customer Paula Delbarco said she was shocked anyone would target a store popular with children, a place she relies on year-round for special supplies.

"I’m really disappointed. I’m really sad that this human being thought this would be appropriate," Delbarco told CBC News.

The Halloween season is the Amazing Party Store's busiest time of year, and the owner estimates he has lost about half a million dollars in business.

Police have not yet said whether the three packages found since Monday contain explosives.