MEXICO CITY, Dec. 9 (Xinhua) -- Four people have died in Mexico due to the cold snap that began in October, the country's Health Ministry said in a Sunday report.

    The deaths in the northern states of Chihuahua and Tamaulipas and the central states of Puebla and Queretaro were all caused by carbon monoxide poisoning.

    Hundreds of families in poorer mountain areas in the country use wood to heat their houses, many with cardboard roofs.

    A new cold front, Mexico's 11th of the season, is affecting the northern states of Chihuahua, Durango and Sonora, and the northeastern state of Baja California.

    Every year dozens of people die during the nation's cold season, mainly from carbon monoxide poisoning. According to official data, 115 people died during winter of 2006.