Baltimore Ravens running back Ray Rice and his fiancee were arrested in NJ on Saturday morning after cops say they STRUCK EACH OTHER inside an Atlantic City casino ... TMZ Sports has learned.
The Atlantic City PD tells us officers responded to a domestic dispute the Revel Casino at 2:51 AM involving Ray and his fiancee Janay A. Palmer.
Cops say ... "After reviewing surveillance footage it appeared both parties were involved in a physical altercation. The complaint summons indicates that both Rich and Palmer struck each other with their hands."
Both Ray and Janay refused medical attention -- and no injuries were reported by either party.
They were transported to a nearby police station where they were booked for Simple Assault-Domestic Violence. They were both released on a summons to appear in court.
A rep for the Ravens issued a statement saying, "We are aware of the Friday night situation with Ray Rice and his fiancee. We have spoken with Ray, and know that they returned home together after being detained."