ATR-42 FLT CREW HAS A TCAS RA DURING APCH TO TUPJ.

Narrative

WE WERE CLRED FOR THE VISUAL APCH WITH TWR; AND INSTRUCTED TO FLY OVER THE ARPT AND MAKE A R DOWNWIND. TWR INFORMED US TFC WAS TAKING OFF AND SAID TO ADVISE THEM OF R BASE. WHEN TURNING R DOWNWIND OVER THE FIELD WE ADVISED TWR THAT WE WERE TURNING DOWNWIND AND STARTED OUR DSCNT. A FEW SECONDS LATER TWR ASKED OUR ALT AND AT THAT TIME WE WERE AT 2600 FT. THEY ADVISED TFC WOULD BE OFF OUR L SIDE. WE HAD THE OTHER ACFT ON TCAS AND THEY PROCEEDED TO GET CLOSE TO US. THEN THE ACFT APPEARED TO TURN TOWARD US MORE AND WE THEN PICKED THEM UP VISUALLY. A FEW SECONDS LATER WE RECEIVED AN RA TELLING US TO CLB. WE COMPLIED WITH THE RA AND CLBED. AT THE TIME TWR STARTED CALLING US TO ASK OUR ALT AND IF WE HAD TFC IN SIGHT. I RESPONDED WITH THAT WE RECEIVED AN RA AND WERE CLBING AND ADVISED OUR ALT WE WERE PASSING THROUGH. THEY THEN STATED FOR US TO MAINTAIN 2800 FT AGAIN AND TURN S. AFTER LEVELING OFF AND TURNING S; THE SITUATION WAS RESOLVED. THE EVENT OCCURRED IN NIGHT VMC AT AN ICAO OPERATED ARPT (TUPJ). I AM UNSURE OF THE OTHER ACFT'S CALL SIGN AS NO COMS WERE MADE TO THEM.