Officials provided few details of the arrangement signed in a public ceremony by the head of the International Red Cross and Interior Secretary Miguel Angel Osorio Chong.
The Red Cross said in a statement that it would provide "studies, protocols and technical assistance related to the search for the disappeared" but gave no specifics. Red Cross officials said they could not release a copy of the agreement, and the Interior Department did not immediately respond to requests for a copy.
The agreement was signed a day after Human Rights Watch released a report that describes 249 cases of disappearances, most of which appeared to have been carried out by Mexico's military or law enforcement. Also on Wednesday, Mexican officials said they had a preliminary count of more than 27,000 people reported missing over the last six years, the majority of the cases blamed on drug cartels or smaller gangs.
Interior Subsecretary for Human Rights Lia Limon told MVS Radio on Thursday that the government would work to collect DNA from families of the disappeared, data that she called key to matching missing persons' reports with the thousands of unidentified corpses found around Mexico in recent years.
She said the federal Attorney General's Office had assembled a list of 27,523 missing people and the government is working to add to the sometimes sketchy information. She said the database would be constantly updated.
A civic organization released a database late last year that it said contained official information on more than 20,000 people who had gone missing in Mexico since former President Felipe Calderon began his six-year term Dec. 1, 2006, and launched a campaign against cartels. In posting the database on its website, Propuesta Civica, or Civic Proposal, said the information was collected by the Attorney General's Office.
The missing in Propuesta Civica's database include police officers, bricklayers, housewives, lawyers, students, businessmen and more than 1,200 children under age 11. They are listed one by one with such details as name, age, gender and the date and place where the person disappeared.
The Human Rights Watch report said security personnel sometimes work with criminals, detaining victims and handing them over to gangs. The report cites incidents in which investigators used information collected in a case to pose as kidnappers and demand ransom payments from the victims' families.
Authorities frequently fail to take even the most basic investigative steps, such as tracing victims' cellphone or bank records, and often rely on investigations carried out by the victims' relatives, the report says.
Human Rights Watch recommended that the Mexican government of new President Enrique Pena Nieto take concrete steps to change security procedures, including issuing new rules requiring that detainees be taken immediately to prosecutors' offices and not be held at military bases or police stations.