PORTLAND, Ore. (AP) — Authorities say a minor explosive device detonated inside a portable restroom at a softball game in an Oregon park, injuring one person.

Washington County sheriff’s spokesman Vance Stimler says bomb squad experts believe the device could have done more damage when it exploded Saturday afternoon at the park outside Beaverton, a city 7 miles west of Portland, Oregon.

A woman suffered non-life-threatening injuries.

Stimler says the device was constructed from chemicals available at most grocery stores that would detonate when the chemicals combined. Stimler declined to identify the chemicals involved.

A nearby school also was searched and cleared later Saturday.

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