Three Australian survivors of the Bali bombings in 2002 have faced the man accused of building the explosive devices.
Umar Patek has admitted to mixing the chemicals, but says he played no part in assembling the bombs which killed 202 people, including two New Zealanders in the tourist district of Kuta.
Prosecutors have asked three of the survivors - Jason McCartney, Peter Hughes and Stuart Anstee - to testify at the trial in Jakarta.
Speaking outside the court, Mr McCartney and Mr Hughes said it is important that they shared their experiences.
Mr Hughes was badly burned in the attacks and is calling for the death penalty to be imposed.