Mexico's Secretary of the Interior Francisco Blake Mora addresses the audience during a news conference in Mexico City in this October 4, 2011 file photo. [Photo/Agencies]

MEXICO CITY -- Mexican Interior Minister Francisco Blake was killed in a helicopter crash on Friday, a blow to the government as it fights powerful drug cartels.

Television images showed the scattered wreckage of the helicopter on a green hillside south of the capital where Blake and the seven others on board were killed.

President Felipe Calderon said conditions were cloudy when the helicopter came down so that an accident looked probable.