Three International Rescue Committee workers and their Afghan driver were killed Wednesday in a Taliban ambush in central Afghanistan, police reports say.

The aid workers, all women, were killed in the Qalah Rahmat area of Puli Alam, the capital of Logar province, Abdul Majeed Latifi, provincial security chief, said.

"The workers are citizens of Ireland, Canada and the United States," said Latifi, who moved the aid workers' bodies to the provincial hospital.

He said the attackers escaped from the area and police were deployed there to track them down.

Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack and said Taliban fighters had killed three foreigners, two women and one man.

"One of the enemy's vehicles was destroyed by a rocket-propelled-grenade shot, killing three foreigners, but the other vehicle managed to escape from the area," Mujahid told dpa by phone from an undisclosed location.

"Our mujahedin seized some of the ammunition from the destroyed vehicle," he added.

Governor Abdullah Wardak also confirmed the attack and said the workers were on their way from Gardiz, the capital of neighbouring Paktia province, to Kabul.

Officials from the International Rescue Committee, an international relief group that helps people fleeing conflict and persecution, were not immediately available for comment.

Attacks on aid workers have increased this year as the Taliban, the former Islamic fundamentalist ruler of Afghanistan, stepped up its insurgency after a lull in the fighting during the winter.

At least 19 aid workers had been killed in the country so far this year while violence has also hampered the delivery of aid to remote areas in the south and east, according to the Agency Coordinating Body for Afghan Relief.

More than 2,700 people - mostly insurgents, but also including about 1,000 civilians - have been killed so far this year in fighting in Afghanistan.