VANCOUVER, Wash. (KOIN) — People quickly evacuated the Clark County Historical Museum Wednesday after a package exploded.

A small foil package had been shoved through the mail slot at the museum located on Main Street in downtown Vancouver.

A Google Street View image of the Clark County Historical Museum in downtown Vancouver, Washington, June 2018. (Google)

Museum staff and volunteers were inside the building when the package was found just before 12 p.m.

Bradley Richardson, the executive director at the museum, was taking a closer look at the item when it suddenly exploded.

No one was hurt and the building was quickly evacuated.

Vancouver police officers said the package was a so-called “bomb bag.” The novelty packets — which are often used for pranks — combine baking soda and vinegar and explode about 20 seconds after being squeezed.

A so-called "Bomb Bag" combines baking soda and vinegar and explodes when it's squeezed, April 24, 2019. (KOIN)

Officers launched an investigation into the explosion. Cameras at the museum appeared to capture images of teenagers pushing the package through the mail slot.

This isn’t the first time a bomb bag has been set off in the area.

A business next door to the museum also had bomb bags recently set off in its store.

The packages are sold at a magic shop about a block away.