Between 1976 and 1983 Argentina was governed by a military junta that waged a brutal dirty war against its opponents.
Approximately 30,000 people disappeared during this time. Among the desaparecidos were leftists, trade unionists, students and activists.
In the protests the mothers wear white head scarves to identify themselves to each other and as a representation of their child's blanket.
Three of the original fourteen mothers were disappeared by the junta, with their remains later found and their identities proven through DNA testing.
In 1986 the original mothers group, now numbering hundreds, split into two factions: the Founding Line, which held its original goals, and the Association which is more political and radicalized. They are the larger and louder group at the plaza this day.
Another group is the Abuelas de Plaza de Mayo. These are the Grandmothers, an organisation dedicated to finding the stolen babies, whose mothers were disappeared and killed after giving birth. The babies were adopted to wealthy families with connections to the junta. It is estimated that there are over 400 stolen babies, and about 100 have been discovered to date.
The mothers, and their supporters, read out the names of the missing children as they march around the plaza, often with pictures of the missing.
In some ways these Thursday afternoons seem to have become an event for tourists and camera crews. On this day we saw television crews from KBS in Korea, and NHK in Japan.
The message remains important and we should never forget what happened during that terrible time. The current government appears committed to bringing those responsible, after all these years, when there are many who would rather forget and move on, to justice.
I found the public naming of names, coupled with the photos of the missing, to be a moving experience. At the time of the dirty war, I was the age of the some of the desaparecidos, and the faces on the posters remind me of my friends, and of myself.