NEW : Police nearing museum , archaeological center in ancient city , official says . Two individuals killed : a 65-year - old man and a 77-year - old woman . About 30 meters away Police report a gas ##eous explosive device near museum . The Greek prime minister has declared a nationwide state of emergency .
NEW : Police nearing museum , archaeological center in ancient city , official says . Two individuals killed : a 65-year - old man and a 77-year - old woman . Police report a gas ##eous explosive device near museum . The Greek prime minister has declared a nationwide state of emergency .