Mexico drugs war: Security forces 'committing abuses'
Mexico's security forces are committing widespread abuses in the fight against drug gangs but are not being held to account, Human Rights Watch says.
The group says its research suggests the military and police participated in 24 killings and 39 disappearances.
It urges the Mexican government to ensure the civilian authorities investigate alleged abuse by soldiers.
In response, President Felipe Calderon said his government was working hard to improve protection of human rights.
He added that the main threat to human rights was from criminals, and the state had an obligation to confront them.
Some 40,000 people have died in drug violence since late 2006 - officials say most of the victims were criminals.
Human Rights Watch says its findings after two years of research in some of Mexico's most violent states strongly suggest the involvement of security forces in rights violations.
As well as extra-judicial killings and disappearances, the US-based group says it documented more than 170 cases of torture.
"Instead of reducing violence, Mexico's 'war on drugs' has resulted in a dramatic increase in torture and other appalling abuses by security forces," said Jose Miguel Vivanco, Americas director at Human Rights Watch.
President Calderon began deploying troops against organised crime gangs shortly after taking office in late 2006.
To date some 50,000 soldiers have been used, as well as members of the Navy, federal police and state and local police forces.
According to the latest official figures, from January, about 35,000 people have died. However, other estimates suggest the number now exceeds 40,000.
Human Rights Watch says it found evidence in the states it examined - Baja California, Chihuahua, Guerrero, Nuevo Leon and Tabasco - that soldiers routinely use torture to get information about cartels.
The group says none of the cases of alleged abuse it documented are being properly investigated.
Despite rulings by Mexico's Supreme Court, soldiers accused of violations against civilians continue to be investigated and tried under military jurisdiction.
The result, according to Human Rights Watch, is near impunity.
In the five states, military prosecutors opened 1,615 investigations between 2007 and April this year into crimes allegedly committed by troops. No soldier has been convicted.
Human Rights Watch says civilian prosecutors also fail to properly investigate human rights abuses.
In a statement on the presidency website, Mr Calderon defended his policies, saying that the "main threat to the human rights of Mexicans is from criminals".
It added that it was "the ethical and legal obligation of government to deploy all means at its disposal" to fight criminals.
"In recent years, Mexico has taken decisive steps for the promotion and protection (of human rights)," the statement added.