A military investigator testifying before the special tribunal in Juba has alleged that the army’s deputy chief failed to respond to advance intelligence warning of a deadly assault on the Nasir garrison earlier this year.
The claim was made during the ongoing treason trial of suspended First Vice-President Dr. Riek Machar and seven others.
Major Peter Malual Deng, the prosecution’s first witness, told the court that Lt Gen Gabriel Duop Lam — who was serving as acting Chief of Defence Forces at the time — was briefed on an imminent attack targeting the South Sudan People’s Defence Forces (SSPDF) base in Nasir County but neither escalated the information to senior leadership nor took preventive steps.
The 3 March 2025 attack on the Upper Nile base left more than 250 soldiers dead, including senior commander Gen David Majur Dak, as well as a crew member aboard a UN helicopter. Prosecutors argue the assault was coordinated by the White Army militia alongside elements loyal to Machar’s SPLA-IO.
Machar, 73, and his co-accused are facing charges of treason, murder, and crimes against humanity before a three-judge panel.
“Did not take action”
During Monday’s 27th session at Freedom Hall, Maj Malual — part of a joint military investigation team — said Gen Duop was effectively heading the SSPDF when the intelligence was received because the army chief was abroad.
“He was told about the planned attack on Nasir and neither acted nor informed the leadership,” Maj Malual testified.
Machar’s lead lawyer, Warnyang Kiir Warnyang, challenged the witness on why the matter was not processed through established ceasefire dispute mechanisms, as had been the practice following earlier White Army clashes. Malual responded that this time, the militia and SPLA-IO fighters “lacked patience for that process” and instead coordinated attacks on relief convoys en route to Nasir.
Scope of the probe
Another defence lawyer, Kur Lual Kur, pressed the witness on whether the SSPDF had followed protocol by notifying the Ceasefire and Transitional Security Arrangements Monitoring Mechanism (CTSAMM) about troop deployments — a requirement under the 2018 peace agreement. Maj Malual said this issue fell outside the remit of his committee.
He added that although the initial dispute appeared to be with the White Army, investigations later linked SPLA-IO commanders to the attack.
Kur further questioned whether investigators had secured audio evidence of an alleged call between Machar and local authorities in Nasir. The witness said the committee was not yet constituted when the call supposedly took place.
He also confirmed the deaths of seven SPLA-IO officers who were killed alongside Gen Majur during the final evacuation attempt but noted that investigators were unable to verify their identities.
The defence additionally probed the role of accused lawmaker Gatwech Lam Puoch. Maj Malual responded that although the MP could spread propaganda, he was unlikely to openly urge rebellion, referencing a video in which Puoch objected to SSPDF deployments to Nasir.
Trial adjourned
Presiding Judge James Alala Deng adjourned the proceedings to Friday, 5 December, when cross-examination of Maj Malual will continue.
Lt Gen Duop — who also serves as SPLA-IO chief of staff — is among the eight defendants, alongside Dr Machar, Puot Kang Chuol, Mam Pal Dhuor, Gatwech Lam Puoch, Camilo Gatmai Kel, Mading Yak Riek, and Dominic Gatgok Riek. All eight have denied the allegations.
