Nairobi - Survivors of a university massacre in Kenya where Islamist gunmen killed 148 people have recounted scenes of terror at a trial of five men linked to the slaughter. The deadly attack at Garissa University in northeastern Kenya on April 2 2015, was claimed by Somalia's al-Qaeda-linked Shabaab insurgents.It was the East African nation's deadliest attack since the 1998 bombing of the US embassy in Nairobi.Four gunmen involved in the massacre were killed, but five others have been charged with 162 counts of terrorism and conspiracy to commit an attack, with the trial underway in the Kenyan capital. The five accused are Mohamed Ali Abdikar, Hassan Aden Hassan, Sahal Diriye and Osman Abdi who are thought to be Kenyan or Somali nationals and Rashid Charles, a Tanzanian national.They have denied the charges.Reporting for dutySpeaking to the court in Nairobi, witnesses lined up to testify about the horror they had experienced as masked gunmen staged a terrifying pre-dawn assault on the campus, with their accounts detailed in Kenya's main newspapers.While an early hearing was held in November, the main witnesses began giving evidence this week.During the attack, the gunmen lined up non-Muslim students for execution in what President Uhuru Kenyatta described at the time as a "barbaric medieval slaughter".The trial is set to continue Friday. Prosecution lawyers say they will call around 30 witnesses to give evidence.Garissa University formally reopened this week, for the first time since the massacre, with most of the staff reporting for duty ahead of the new term. About students are expected to begin classes on January 11.