Witness Spomenka Drljevic spoke about the conflict between the HVO (Bosnian Croat Defence Council) and the Army of Bosnia-Herzegovina (ABiH) in the southern city of Mostar in 1993 and 1994.
The 52-year-old witness, a former member of the Bosnian army who held office in the command of the army's fourth corps, first described attacks which Serb forces carried out against Mostar in April 1992.
Drljevic, who is of Bosniak (Bosnian Muslim) origin, told the ICTY that the at the start of the war "the relationship between the HVO and ABiH was fair".
"In HVO units there was a large number of Bosniaks, since HVO had better weapons. However, arguments started about armament," she added.
According to the prosecution witness, the key event happened in January 1993 when the HVO issued an order that all units of ABiH had to become subordinate to the HVO command that proclaimed itself as the only legitimate authority in the area of Mostar.
"Our commanders opposed, showing the attitude of units' members. You could not leave the city without an HVO pass," the witness said.
Besides, more and more ABiH soldiers were arrested, and a great number of soldiers in the black uniforms with no insignia appeared in western Mostar, she said adding that according to their dialect they could have come from Dalmatia (a Croatian region).
She told the court that on 12 May 1993 she watched TV footage made by a Croatian Television reporter, Dijana Culjak, about the apprehension of ABiH members near the 'Vranica' building in Mostar.
Of those detainees who were prisoners of war, 13 are still registered as missing, and the witness said that she hoped that her testimony could help efforts aimed at finding "at least their bodies".
On 13 May 1993, Dreljevic herself was arrested and taken together with another 19 POWs to the HVO-run prison in the southern town of Ljubuski.
They were interrogated in jail, and one of those who questioned Drljevic had the insignia "ATG Kobra -Omis" on his sleeve, according to the witness's testimony. Omis is a town near the biggest Croatian Adriatic city of Split.
The witness went on saying that she and another four female POWs had been correctly treated, while men "looked much worse" and had been forced to labour. While the prison warder Ante Prlic was absent, men of Mladen Naletilic Tuta, an ICTY indictee, used to come and torture the inmates, she said.
Drljevic was kept in the Ljubuski prison until 8 June 1993 when one of the indictees in this trial, Berislav Pusic, came there. They held a conversation about people whom they knew and after that she was transferred to the Heliodrom camp.
The witness will resume her testimony tomorrow.
The trial against Jadranko Prlic, Bruno Stojic, Valentin Coric, Berislav Pusic, Milivoj Petkovic and Slobodan Praljak, former political and military Bosnian Croat leaders, charged with 26 counts of crimes against humanity, violations of the laws and customs of war and grave violations of the 1949 Geneva Conventions, began last week with the opening statement of the prosecutor, Kenneth Scott, and a multimedia presentation of the defence of indictee Slobodan Praljak.