Figures for those killed in Mexico in 2010's drug war have been revised dramatically to 15,273, as civilians are added to the toll in official government figures. The news makes 2010 the most deadly year to date, with just under 10,000 more drug-related murders than 2009. It comes as the country is described as being in a "state of war" by an influential German research organisation.

Since President Felipe Calderón came into power in December 2006, 34,612 people are thought to have died in drug-related killings in the country.

Security spokesman Alejandro Poiré was keen to assure Mexicans that government strategy was working, despite the huge increases in casualty figures. He suggested that the number killed had actually dropped slightly in the fourth quarter of 2010, with some states remaining untouched by drug crime.

He was also keen to highlight that more than half of those on the Attorney General’s most-wanted list published in March 2009 had been captured or killed. In November, Attorney General Arturo Chávez Chávez announced that 12,456 had died in drug wars in 2010 to date, a long way from the figure announced this week.

The staggering numbers make Mexico one of the most deadly places in the world. The Heidelberg Institute for International Conflict Research (HIIK), a research organisation based at the Department of Political Science at the University of Heidelberg, has just published its annual report detailing world conflict.

The war is between the state and drug cartels, with the object of dispute being "regional dominance" and "resources", according to the report which, since 1991, has classified world conflicts according to their intensity.

A large gap exists between highly violent conflict and full-scale war, admits Latin America lead researcher on the project, Friedemann Schirrmeister. "On one hand we take a look at the relative part of the use of violence: how many people use how many weapons and in which way. On the other hand there is an absolute part of the violence which is been used in the conflict. That's simply the question: how much violence is used in that conflict.

"In 2010 we've been observing a dramatic increase of violence in the constellation government: drug cartels. That was our main point."

The news comes days after the discovery of 15 headless bodies in the popular tourist resort of Acapulco, setting a new record for the largest number of decapitated bodies found on a single site.

Police were led to a burning car in the early hours of Saturday morning where they made the gruesome discovery on a pavement in front of a shopping centre. The victims' heads were found piled up some distance away.

A three-way turf war is thought to be breaking out in the region between the Sinaloa, La Familia and Beltran-Leyva cartels. The bodies in Acapulco were found beside messages appearing to be from the Sinaloa cartel, heading by Joaquin Guzmán Loera, or El Chapo, Mexico's most wanted drug lord.