DO-328 flight crew reported and engine fire on takeoff roll. Crew aborted takeoff and returned to gate.

Narrative

During our takeoff roll on Runway XX at ZZZ at around 50 or so knots a Left engine fire RWP was noticed along with the associated Fire Bell and master warning light. The First Officer (FO) who was the PM on this leg called out the RWP. I announced the abort and we performed the memory items for the rejected take off and engine fire prior to V1. The FO announced to the Tower Controller that we were aborting the takeoff. We came to a stop on the Runway and idle/cutoff the engine. The FO pulled and ran the QRH and at that time we noticed the Left engine fire RWP indication extinguished after the left engine was shut down. We exited Runway XX at Taxiway 1 and stopped. We asked the Tower Controller at that time to send an available Ops vehicle for an inspection of the left engine prior to returning to the Gate. ZZZ Ops didn't see any visible damage. Contact was then made to Tower to return to our Gate. The FO phoned Dispatch while I communicated with the Flight Attendants and ultimately announced to the cabin that we would be returning to the Gate after an abnormal indication during our take off roll. We taxied back to the gate on our remaining engine with no further issues.