(CNN) -- A staff member of the aid organization Doctors Without Borders has died after an attack on a vehicle near the capital of South Sudan, the group said Friday. 

The aid worker, Joseph, whose full name has been withheld at the request of his family, died two days after the attack, which took place Monday on a main road outside the capital, Juba, according to Doctors Without Borders. 

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A second employee of the organization was seriously wounded, the group said. 

Doctors Without Borders, also known as Medecins Sans Frontieres, said the "exact circumstances" of the attack aren't yet clear, but the car in which its two staff members were traveling was "clearly marked as belonging to Medecins Sans Frontieres." 

The organization has requested that South Sudanese authorities "investigate the brutal attack that resulted in the killing of our colleague," said Marcel Langenbach, director of operations for the group. 

"We want to emphasize the need to respect international humanitarian law and on the obligation to ensure the protection of humanitarian workers, their property and health facilities," he said. 

Doctors Without Borders said it had been working in the region for more than 30 years. 

South Sudan officially gained its statehood in July 2011 after separating from Sudan. 


how long have they been in the region?
what organization is the article about?
Who is the director of operations?
When did South Sudan separate?
from who?
What is the other name of the organization?
Who was killed?
Do we know his full name?
Why not?
How long after did he die?
How many were in the car?
Was the car marked?
as what?
What is the opinion?
What is to be respected?
and?
Who needs to investigate?
What day did it happen?
what day did the group report it?
What happened to the other worker?
More than 30 years.
Doctors Without Borders said it had been working in the region for more than 30 years. 
Doctors Without Borders
Doctors Without Borders said it had been working in the re
Marcel Langenbach
Marcel Langenbach, director of operations for the group. 

2011
South Sudan officially gained its statehood in July 2011 after separating from Sudan. 
Sudan.
South Sudan officially gained its statehood in July 2011 after separating from Sudan. 
Medecins Sans Frontieres
also known as Medecins Sans Frontieres
Joseph
Joseph, whose full name has been withheld at the request of his family, died
No
 Joseph, whose full name has been withheld at the request of his family
At the request of his family.
oseph, whose full name has been withheld at the request of his fam
Two days.
oseph, whose full name has been withheld at the request of his family, died two days after the attack,
Two
 second employee of the organization was seriously wounded, the group said. 
Yes
but the car in which its two staff members were traveling was "clearly marke
Belonging to Medecins Sans Frontieres.
clearly marked as belonging to Medecins Sans Frontieres." 
We need an Arms Trade Treaty now
Opinion: We need an Arms Trade Treaty now 
International humanitarian law.
need to respect international humanitarian la
Obligation to ensure the protection of humanitarian worker
eed to respect international humanitarian law and on the obligation to ensure the protection of humanitarian worker
South Sudanese authorities
requested that South Sudanese authorities "investigate 
Friday.
attack on a vehicle near the capital of South Sudan, the group said Friday. 
Monday
died two days after the attack, which took place Monday
Was seriously wounded
second employee of the organization was seriously wounded