In South Sudan, while UN vehicles have often been spared, a major exception being a helicopter shot down in December killing four Russian peacekeepers, ambushes of convoys carrying South Sudan's local forces is common because the road network is minimal.
At the time of independence in July 2011, the nation had barely 200 km of black-top roads. The only other connectivity, thus, is via a decrepit riverine network over the White Nile and seasonal roads made of "morrum" and black cotton soil.
In the parts that experience heavy rains, even this makeshift network becomes un-operational, typically from June until December.
Jonglei, the largest of the 10 states of this country spanning a massive 122,000 sq km in the east, has seen many deaths in recent months, including 150 people during battles between the South Sudanese military and insurgents led by local rebel leader David Yau Yau.
It isn't yet clear if and why Yau was behind the latest attack.
