An international aid group in Afghanistan is suspending its activities there after four employees were shot and killed near the capital, Kabul.
The International Rescue Committee says it is stunned by the attack, which left three foreign women and their Afghan driver dead.
A second driver was wounded when unidentified gunmen fired on the group as they drove through Logar province.
Two Afghan staffers of IRC were killed in an ambush in Logar a year ago.
International aid groups have been unable to operate in many southern provinces for some time because of the lack of security.
Aid groups say 19 non-government workers had been killed in the first seven months of the year, more than the number for the whole of 2007.
Three Europeans and two Afghans working with Medecins Sans Frontieres (Doctors Without Borders) were killed in 2004 in the western province of Badghis.
Last month, two French aid workers were kidnapped in central Afghanistan. They were freed after more than two weeks.