Mexico's top human rights official said Friday that a 10-year-old Guatemalan girl who died in custody fell from a bunk.

Immigration officials originally said Thursday that she arrived at a Mexico City detention center complaining that her throat hurt. Interior undersecretary for human rights Alejandro Encinas later said that explanation was true, but not related to her death.

Encinas said the girl died of trauma after falling in the dormitory where her mother was located.

The girl died Wednesday night after arriving the day before with her mother from the northern border state of Chihuahua.

Encinas did not clarify why officials made no mention of the fall when they reported her death Thursday. An investigation has been opened.

Authorities have not released the girl's name, and on Friday Guatemala's Ministry of Foreign Affairs said the girl's family had decided not to make any comment on the death or release any additional information.

The ministry said it expected the girl's body would be returned soon to her family in Guatemala City.