BERLIN — Authorities in the German city of Darmstadt say a 39-year-old American man is suspected of killing his 37-year-old partner before dying in as yet unclear circumstances.

Prosecutors said police found the woman lying lifeless on the street after witnesses reported hearing gunshots early Monday.

Officers confronted the man shortly afterward in nearby gardens. Prosecutors said "the armed suspect died under circumstances that haven't been fully determined yet."

Authorities declined to provide further information, including the identities of those involved, citing the ongoing investigation.