Las Cruces, N.M. • Federal immigration authorities have confirmed that a 7-year-old girl who crossed the U.S.-Mexico border with her father last week died after being taken into the custody of the U.S. Border Patrol.

The Washington Post reports the girl died of dehydration and shock more than eight hours after she was arrested by agents near Lordsburg, New Mexico. The girl was from Guatemala and was traveling with a group of 163 people who approached agents to turn themselves in.

It's unknown what happened to the girl during those eight hours before she started having seizures and was flown to an El Paso hospital.

In a statement, Customs and Border Protection said the girl had not eaten or consumed water in several days.

The agency did not provide the Associated Press with the statement it gave to the Post, despite repeated requests.