While the Islamic insurgents have targeted a number of Christian foreigners working in Afghanistan, the attacks fit into a rise in violence against aid workers.
"This is part of the Taliban's plan to make life difficult in Kabul," says Haroun Mir, director of the Afghanistan Center for Research and Policy Studies. "Everyone is now a target, especially foreigners working for Christian organizations."
The attack occurred around 8 a.m. Monday when gunmen on motorbikes fired at the aid worker, Gayle Williams, while she was walking to work, witnesses say. The incident took place in a busy section of the capital city that foreigners frequent.
A Taliban spokesman said that the worker was targeted because they believe she was proselytizing. "This woman came to Afghanistan to teach Christianity to the people of Afghanistan, Taliban spokesman Zabiullah Mujahed told the Associated Press. "Our [leaders] issued a decree to kill this woman. This morning our people killed her in Kabul."
The murdered woman, a British national originally from South Africa, was an employee of Serving Emergency Relief and Vocational Enterprises (SERVE), a British-based Christian charity that has been working in the region since 1980. The group's website says that its purpose is to "express God's love and bring hope by serving the people of Afghanistan."
The group has been accused of teaching Christianity to Afghans in the past, says a source familiar with the incident.
Insurgents have eyes and ears in Kabul
The attack suggests that the insurgents have a reliable intelligence apparatus within Kabul that can track Christian charities and other foreigners.
"The Taliban had a very organized government when they were in power, and after their fall many of their people stayed behind in Kabul," says Habibullah Rafeh, a political analyst with the Afghanistan Academy of Sciences based in Kabul.
Ms. Williams did not travel in a marked vehicle, which means the Taliban must have relied on informants in the area to discover that she belonged to a Christian charity, continues Mr. Rafeh. Monday's attack most likely took a good deal of advanced planning, he adds.
Religious freedom not widely protected
The presence of Christian organizations in Afghanistan has been a sensitive issue in recent years. The population of Afghan Christians is small – less than 1 percent of the population. They often worship in secret, for fear of reprisal from neighbors. Churches are more concentrated in Kabul and in northern cities, where the Taliban has less of a presence.
A handful of Christian NGOs that operate in the country, such as Christian Aid and Catholic Relief Services, although members usually say they are only involved in humanitarian and not religious work.
Although the Afghan Constitution does not prohibit the practice of different religions, the preponderance of religious conservatives in the country's judicial system and among community leaders has meant that religious freedom is greatly inhibited.
"We are not a normal country – we are at war," says Mr. Mir, the analyst. The government worries that if it doesn't shore up its Islamic credentials, this will be of propaganda use to the Taliban, he explains.
In January, a Christian woman working for an international aid organization was abducted in Kandahar, in southern Afghanistan, although it is unclear whether the motive was related to her religious background.
Last year the Taliban abducted a bus load of 23 South Korean missionaries on the Kabul-Kandahar highway. Two were killed but 21 were freed after extensive negotiations.
In 2006, an Afghan court sentenced an Afghan man to death for converting to Christianity. Pressure from international groups forced the Afghan government to allow him to leave the country, and he was eventually granted exile in Italy.
Attacks on aid workers up
The attack comes at a time when the threats posed to international NGOs working in the country are at an all-time high. A report released last week by the Afghanistan NGO Safety Office (ANSO), a body that monitors NGO activity in the country, says that there have been 146 incidents of violence against NGOs so far this year, already more than in all of 2007. This marks the highest rate since ANSO began keeping track of attacks in 2002.
Kidnappings and general insecurity have also been on the rise. This year has seen "unprecedented levels of violence," according to the ANSO report. "Many South and East districts have arrived at the saturation point with little territory remaining for the [Taliban] to take."
Kabul has also seen a spate of kidnapping in recent weeks, including the abduction of a high-profile former presidential candidate on Sunday.