“The highest quantity of murders, 15,273, was recorded in 2010,” security spokesman Alejandro Poire told a meeting with citizens’ defense groups on national security.

Mr. Poire said around half of the killings had been in three northern states, Chihuahua, Tamaulipas and Sinaloa, and that the murder rate had slightly reduced toward the end of the year.

The figure for 2010 was almost half the last official figure for the total killed since Mr. Calderon launched a military offensive on the country’s powerful gangs, involving some 50,000 troops, in 2006.

Rights groups have underlined complaints of army abuses under the crackdown, which has been accompanied by a rise in violence.