Red Cross worker Khalil Dale joins a roll call of humanitarian aid workers killed in war-torn states.
After the death of Karen Woo in Afghanistan in August 2010, researchers claimed aid workers were four times more likely to be killed than they were in the 1990s.
At the time, the Overseas Development Institute said the overall number of deaths had soared nearly four-fold in a decade.
Dr Woo was killed while working with the International Assistance Mission in Afghanistan. The 36-year-old, from Stevenage, had given vital medical help to up to 2,000 people during the expedition, her inquest heard in December.
Her death was not the first time an aid worker had been targeted in Afghanistan.
In October 2008, Gayle Williams, who had dual British and South African citizenship, was killed by two gunmen on a motorcycle as she walked to work in the capital Kabul.
In 2007, 23 South Korean aid workers from a church group were taken hostage in southern Afghanistan. Two were killed and the rest released.
In 2001, eight international aid workers, including two Americans, were imprisoned and charged with preaching Christianity.
In October 2010, Linda Norgrove, from Lewis in the Western Isles of Scotland, who was employed by US aid group DAI, was killed during an attempt to rescue her.
The 36-year-old had been seized with three local staff in the eastern province of Kunar on September 26 that year, and was killed by her captors the following month during a rescue mission by US forces.
In August the same year, 10 men and women working for a Christian aid agency, including a British woman, were murdered by Taliban. A Taliban spokesman later said they had been killed because they were missionaries and spies for the United States.
Other war-torn areas have also claimed the lives of humanitarian workers.
Irish aid worker Margaret Hassan, 59, had worked in Iraq for many years until she was abducted and murdered by unidentified kidnappers in Iraq in 2004.
The Overseas Development Institute warned that aid work had become more risky than UN peacekeeping as attacks become increasingly politically motivated in some countries.
Researchers Abby Stoddard and Adele Harmer wrote: "Although there has been improved and professionalised security management, humanitarian organisations are unable to secure their personnel in a small number of the most dangerous operational settings, particularly Afghanistan and Somalia, where they are perceived as part of Western geopolitical interests."