The trials are of Catholic Priest Hormisdas Nsengimana and of former officers of the former Rwandan Armed Forces (RAF) in a joint case known as "Military II".
In the latter case, which opened in September 2004, General Augustin Ndindiliyimana, former Chief of Staff of Rwandan Gendarmerie, began Wednesday to resent his defence case.
General Ndindiliyimana is defended by Christopher Black and Vincent Lurquin.
The witness list had at the beginning 80 names, but the list is reliably learnt to have been reduced. The session is scheduled to last until 14 March.
The first witness was Colonel Luc Marchal, who commanded the Kigali sector for the United Nations troops in 1994. The Belgian officer, now retired, came to testify over what he experienced in Rwanda.
After the opening statement on Monday by Mr Black, the examination in chief lasted for two days. Other lawyers crossed-examined him Friday.
It will be the prosecutor's turn for cross examination next Monday and Tuesday. Ndindiliyimana, is the second defendant in the joint trial of four officers.
In another chamber, Father Hormisdas Nsengimana saw himself being opposed by several witnesses of the prosecution.
The trial began briefly on 22 June with five witnesses having testified against the Head of the College of Christ the King of Nyanza, in southern Rwanda.
Since Monday, six other witnesses have appeared in court, accusing the clergyman of having participated in various massacres in the vicinity of the College, one of the most prestigious of the country. The prosecution intends to call 21 witnesses.
Next week will see the resumption of the Butare trial, the "oldest" of the tribunal. The trial is also the largest with six defendants.
The former mayor, Joseph Kanyabashi, the second last defendant to present his defence case, is at the third of his witness list. The chamber has asked him to finish his defence in April so that the proceedings can end in July.
Proceedings in the Simeon Nshamihigo, former Deputy Prosecutor in Cyangugu,Southern Rwandan, during the genocide, are scheduled to resume next Wednesday. The trial started in September 2006.
PB/ER/SC
@Hirondelle News Agency