The International Press Institute (IPI) today urged authorities in South Sudan to apprehend those behind an ambush attack last weekend on the two-car convoy of a local official that left five local journalists dead.

Unidentified heavily-armed men attacked the convoy of County Commissioner Maradom James Benjamin on Sunday while it travelled in western Bahr al-Ghazal State following Benjamin’s visit to the victims of a previous attack targeting vehicles of the Sudan People’s Liberation Army (SPLA).

Benjamin escaped the ambush, but six other civilians were killed and four were wounded, bringing the total number of deaths to 11. Some sources have reported up to 13 deaths.

The slain journalists have been identified as state Raja FM radio station director Musa Mohamed Dhaiyah; Raja FM reporters Randa George Adam, Dalia Marko and Adam Juma; and South Sudan Television (SSTV) cameraman Boutros Martin.

In a statement yesterday, South Sudanese military spokesperson Col. Philip Aguer said that the attack bore the hallmarks of Ugandan armed group the Lord’s Resistance Army (LRA). However, Western Bahr el Ghazal State Governor Rizik Zachariah Hassan dismissed the allegation, asserting that the ambush was carried out by South Sudanese* rebels led by former Vice President Riek Machar.

No group has claimed responsibility for the attack.

South Sudan is in the midst of a violent civil conflict caused by a rift in the political leadership between President Salva Kiir and Machar. Fighting between government forces and armed rebel factions broke out in December 2013, destabilising the country and weakening the rule of law. Thousands have been killed, and nearly two million South Sudanese have been displaced. This weekend’s roadside attack is the second such ambush in the county in two weeks.

“We urge South Sudan’s government to determine who was behind this attack and to bring them to justice,” IPI Director of Advocacy and Communications Steven M. Ellis said. “Journalists play a vital role in disseminating accurate information, an essential resource that civilians rely on even more heavily during times of conflict and uncertainty. This devastating attack demonstrates the vulnerability of journalists and other civilians, and the extraordinarily difficult and dangerous circumstances under which journalists in South Sudan operate.”

*This statement was corrected on Jan. 29, 2015, to note that those allegedly responsible for the ambush were South Sudanese, not Sudanese, rebels.