A military court in Mexico has charged three high ranking officers with murder in the cases of 143 leftists and dissidents during the 1960s and 1970s.

Two of them, General Francisco Quiros and General Mario Arturo Acosta were already being held on drugs charges.

The other man, Major Francisco Barquin, was arrested on Wednesday.

The case marks the first time generals are being charged in connection with the so-called dirty war in which hundreds of activists were killed or went missing.

The relatives of disappeared leftists have reacted with caution, saying the trials are held by military courts behind closed doors.

When President Vicente Fox's administration took over from the Institutional Revolutionary Party two years ago, he nominated a special prosecutor to investigate the dirty war crimes and promised to punish past corruption.

From the newsroom of the BBC World Service