An overwhelming majority of immigrants who cross via Mexico are from Guatemala, El Salvador and Honduras, and consular officials from those nations report even higher numbers of dead. They said more than 260 of their people had died along this border last year.

And in cemeteries around the southern border capital of Tapachula, Salvadoran officials said, there are dozens of unmarked graves of immigrants who have never been identified and whose deaths are not counted by any nation.

Local human rights advocates, whose shelters are often overrun with immigrants battered by crime, said the numbers reveal only a fraction of the horror.

Immigration officials said that among the migrants killed along the border this year was Milton García, 28, a Honduran who died from a machete blow to the head. In February, the dismembered body of Dany Vladimir España, 18, of El Salvador was found on the train tracks that run through Tapachula. And in May, officials found the body of a 48-year-old Guatemalan named José Otilio Navarro that showed signs of torture.