Complex sentence: On 26 April 1985, at about 6 pm, a group of prisoners rose in rebellion, when only two of 70 Afghan Mujahideen were guarding the prison, while the others were gathered on the drill square performing evening prayers ("namaz").
Split into simpler sentences: On 26 April 1985, at about 6 pm, only two of seventy Mujahideen guards were on duty. The others were gathered on the drill square for evening prayers ("namaz").