Mexican prosecutors plan to file genocide charges this year against former officials in connection with a 1968 massacre of student protesters.

The announcement was made Thursday by Ignacio Carrillo, the special prosecutor in charge of investigating crimes allegedly committed by the government during Mexico's so-called "dirty war" of the 1960s and 70s.

The charges expected to be filed stem from an October 2, 1968 incident, when soldiers fired on a large group of demonstrators gathered in Mexico City's Tlatelolco Plaza.  An undetermined number of people were killed.

Former President Luis Echeverria - who was interior minister at the time - is said to be under investigation for his role in the incident.

Some information for this report provided by AP, Reuters.