This was the scene of the worst recent violence in which security forces killed at least 70 protesters.
Soviet security forces are estimated to have killed at least 200 protesters on the square.
He was also serving there in 1990, when Soviet troops killed more than 100 protesters.
Two days later, the police killed four more protesters in Aden.
The live rounds killed 12 protesters and injured about 190.
Officials said a gun battle with the police killed two protesters and left three officers in critical condition.
During the protests of 1968, Mexican government killed students and civilian protesters.
Police had killed 12 Muslim protesters after a brief altercation with them.
"I am a free woman, and attacking this woman or killing protesters is just like going after one of my own children."
A military picket shot at the crowd, killing several protesters and setting off a series of violent events.