POSTED: Sunday, March 11, 2012 - 8:00pm
UPDATED: Sunday, March 11, 2012 - 8:04pm
NBC NEWS — The remains of 167 people have been found in a cave in southern Mexico.
Forensic experts believe the remains are at least 50 years old.
They were found on Friday, March 9 in an area frequented by Central American migrants traveling north.
Authorities say the remains showed no visible signs of violence but that they were investigating.
In the past two years, mass graves have been discovered mainly in northern Mexico and containing the bodies of dozens of migrants.
They are thought to have been killed by drug cartels.