Mexico City ? Homicides related to organized crime jumped 47 percent in 2008, Mexico’s attorney general said Friday in a rare confirmation of how bad violence has become.

Police later made two gruesome discoveries in northern Mexico. Five bodies – two of them decapitated – were found wrapped in blankets in a city on the border with Texas, along with two heads in sacks. In another state, police found four severed heads in ice chests along a highway.

Attorney General Eduardo Medina Mora told Radio Formula that 1,378 people have been killed so far this year, compared with 940 in the same period last year.

The statistic reflected what many in Mexico already knew: Drug-related killings have soared in recent months.

But the details were the first official snapshot on the rise in killings. The Mexican government has been reluctant to release homicide statistics, leaving the public to rely on informal tallies by the news media.