A man hacked inmates to death on Monday before being shot dead by a prison officer in Twic County, Warrap State, according to an official.

Manut Deng, 35, had been serving a three-year jail term for murder.

However, authorities say the former prison administrator, who happened to be Deng’s relative, decided to keep him in his house, though he would frequent the correctional facility.

“When Capt. William handed over the prison administration to me, he kept this prisoner in his house. He was serving number of sentences in the prison,” said Maj.-Gen. John Machar, Twic County Prison director.

On that fateful day, and armed with an axe, Deng allegedly attacked Mathiang Ring and Deng Mabur – killing them before being gunned down.

Ring and Mabur were aged 67 and 78, respectively.

“The deceased were among the elderly inmates that I allowed to sleep in front of my office for safety reasons,” Machar continued.

Other prisoners who sustained injuries during the attack include Achol Deng and Nyuon Chol, and prison officer named Dut Maker.

Maj.-Gen. Machar added that the motive behind the attack on Twic County prison, which is home to 312 prisoners, is still unknown.