Investigators have started exhuming unidentified bodies at two burial grounds in the southern state of Chiapas in an effort to determine if they are those of migrants who disappeared in Mexico while trying to reach the United States, the State Human Rights Council, or CEDH, said.

The cases of 429 migrants from different countries who disappeared in Mexico have been documented, the CEDH said.

The exhumations, which started on Monday and will continue until Sept. 16, are being done at the Tapachula and Ciudad Hidalgo cemeteries near the border with Guatemala, the council said.

The Argentine Forensic Anthropology Team, a non-governmental scientific organization, is assisting in the process, the CEDH said.

The exhumations are being done under an agreement signed in February by several human rights groups, state officials and the Argentine specialists to establish a forensic database for missing migrants, the CEDH said.

The project's goal is to try to find Central American migrants who disappeared near the Tapachula and Ciudad Hidalgo border crossings in southern Mexico.

Dental, genetic and anthropological information gathered from the unidentified bodies will be compared by the Argentine specialists to information about missing migrants from El Salvador, Honduras and Guatemala.

The forensic databases were created recently as part of the Frontera Project, whose goal is to establish a regional agency to improve the search for people, especially migrants, reported missing in Central America, Mexico and the United States, the council said.

An estimated 300,000 Central Americans undertake the hazardous journey across Mexico each year on their way to the United States.

The trek is a dangerous one, with criminals and corrupt Mexican officials preying on the migrants.

Gangs kidnap, exploit and murder migrants, who are often targeted in extortion schemes, Mexican officials say.

Central American migrants follow a long route that first takes them into Chiapas state, which is on the border with Guatemala, walking part of the way or riding aboard freight trains, buses and cargo trucks.

The flow of migrants has increased markedly in the northern and northeastern parts of Mexico since U.S. officials increased security along the border in the northwestern part of the country.

A total of 46,716 Central Americans were deported from Mexico between Jan. 1 and Nov. 30, 2011, the INM said in a report released earlier this year.

The majority of the migrants - 41,215 - were men and nearly half, some 23,560, were from Guatemala, the National Migration Institute, or INM, said. EFE