MEXICO CITY, Dec. 27 (Xinhua) -- The ruins of an ancient pyramid in central Mexico City may indicate that the area was inhabited at least 100 years earlier than previously thought, Mexican archaeologists said Thursday.

    The 11-meter pyramid, found in the central Tlatelolco area last month, could have been built by the Aztecs in 1100 or 1200 A.D., according to archaeologists.

    In 1992, another pyramid was discovered in Tlatelolco, a world famous archeological site.

    Since then, historians have thought Tlatelolco was founded by the Aztecs in 1325 as a twin city of Tenochtitlan, the capital of the Aztec empire, which became Mexico City after an invasion by Spanish conquistadors in 1521.

    In August, archaeologists also found what they believe was Tenochtitlan's main pyramid in Iztapalapa, an eastern district of Mexico City.

    The Aztecs, who once ruled an empire stretching from Mexico's Pacific to Atlantic coasts, built massive pyramids across what is now central Mexico.