Arang (2006)

A salt storehouse near the sea may be haunted. A penniless ex-con dies a gristly death in a house he can ill afford. The detectives assigned the case are Min, newly reinstated after a suspension, and Lee, a new transfer from forensics. Min has nightmares: a sexual assault that haunts her. She and Lee work well together, but soon two more deaths occur - each mysteriously poisoned, both friends of the ex-con. A fourth friend, a newly married doctor, is a suspect. But what has all this to do with the salt storehouse, a death ten years ago, and a missing girl? Can Min and Lee get to the bottom of it, or is the supernatural beyond a cop's reach?

Source: TMDb