Twitter Inc. said it has updated its policy on hateful conduct to better protect religious groups, the latest effort by the company to police speech and curb abuse on its platform despite the potential risk of offending some users.

Under the modified terms, tweets with language that “dehumanizes on the basis of religion” will be removed when reported by users or identified by the company itself, the social-media giant said Tuesday. The change was made, in part, in response to a user survey conducted last year that drew more...