Aid agencies say attacks on their workers in Afghanistan are increasing
Taleban gunmen have shot dead three female international aid workers and their local driver near the Afghan capital Kabul.
The three International Rescue Committee (IRC) workers were a Canadian, a British-Canadian and a Trinidadian-American.
Five gunmen carried out an ambush in Logar province and opened fire with Kalashnikovs, a wounded survivor said.
A Taleban spokesman described the aid workers as foreign spies.
Aid agencies are frequently targeted in the Afghan conflict, with convoys attacked and staff abducted or killed.
International aid groups have been unable to operate in many southern provinces for some time because of insecurity.
More recently, violence has been spreading to other areas.
Logar - which lies just to the south of the capital - had been relatively stable but has become increasingly violent in recent months.
The BBC's Alastair Leithead in Kabul says the United Nations now classifies the province as high risk and that violence is encroaching on the capital.
The British-Canadian woman killed has been named as Dr Jacqueline Kirk, 40, a research fellow of the University of Ulster.
Dr Kirk, who had dual British and Canadian citizenship, was affiliated to the university's International Conflict Research centre, based at its Coleraine campus.
The three women and their two Afghan colleagues were travelling from Gardez in the south-east to Kabul in two clearly marked IRC vehicles when they were attacked.
Five men armed with Kalashnikov assault rifles stepped out of a village area and fired at the two vehicles, the surviving Afghan IRC employee was quoted as saying by Abdullah Khan, deputy counter-terrorism director in Logar.
Earlier, another security official reported that gunmen had opened fire on the aid workers from a vehicle.
The bodies were taken to the governor's compound in the provincial capital, Puli Alam.
The IRC said it was "stunned and profoundly saddened".
"Words are inadequate to express our sympathy for the families and loved ones of the victims and our devoted team of humanitarian aid workers in Afghanistan," said IRC president George Rupp.
The organisation announced it had suspended all of its humanitarian aid programmes in the country - after 20 years of operating in Afghanistan.
Taleban spokesman Zabiullah Mujahid said fighters had attacked two vehicles of "the foreign invader forces".
"They were not working for the interests of Afghanistan and they belonged to those countries whose forces... took Afghanistan's freedom," he told the Associated Press by phone.
The aid workers had apparently changed cars for security reasons, and the details of their vehicles may have been passed on to their attackers.
UN special representative to Afghanistan Kai Ede said he was shocked by the attack.
Earlier this month aid agencies warned they may become unable to operate in parts of Afghanistan once seen as safe, because of the intensifying conflict.
AFGHAN AID ATTACKS
2008: An estimated 84 attacks on aid agencies so far, 21 in June
July 2008: Two French aid workers abducted, but later freed
May 2008: UN shuts a repatriation centre in the east amid unrest
Jan 2008: US female NGO worker seized in the south
July 2007: Two South Korean aid workers shot dead
April 2007: Two French aid workers seized in the south-west
March 2007: Gunmen shoot dead a German aid worker in the north
The Agency Co-ordinating Body for Afghan Relief (Acbar), an umbrella group of non-governmental organisations (NGOs), pointed to a 50% increase in insurgent attacks compared to last year.
It expressed its "grave concern about the deteriorating security situation in Afghanistan and the serious impact on civilians".
June saw more attacks on NGOs than in any month since the Taleban's overthrow in 2001 and some agencies had been forced to scale back operations, the statement said.
Nineteen aid workers had been killed so far this year - more than during the whole of 2007, said Acbar.
Some 2,500 people had been killed this year, up to 1,000 of them civilians, Acbar said.
Kabul blamed the rise in insurgent attacks on the Pakistani government's attempts to negotiate peace deals with militants in tribal areas bordering Afghanistan.
Nato commanders have said violence is up by some 40% in eastern Afghanistan since spring this year, partly due to troops patrolling more areas.