Gunmen shot dead seven Pakistani charity workers, six of them women, in an attack in northwest Pakistan Tuesday.

The attack took place about 65 kilometers (40 miles) northwest of the capital in the Swabi district, close to a road connecting Peshawar to the eastern city of Lahore. The victims were Pakistani health and education charity workers at a village community center called Ujala (light), news agencies reported, citing Pakistani officials.

Five of the women were teachers, the sixth was a health worker and the man worked as a health technician, officials said.

They were being driven home from the community center when their vehicle was ambushed by the militants.

"Four men came on two motorbikes. They attacked their van. They opened fire to the right and left of the van and fled on their motorbikes," Swabi district police chief Abdul Rashid Khan said, according to the AFP. “Six women and a man have died. The driver is injured," he said.

The aid group, founded in 1991, has been focusing on Khyber-Pakhtunkhwa Province and on the lawless South Waziristan, a tribal belt bordering Afghanistan.

No militant group has claimed responsibility for the attack, though the recent attacks on aid workers across the country have been attributed to the Pakistani Taliban.

In a series of attacks last month, gunmen killed nine health workers who were taking part in a national polio vaccination drive.

The Taliban claim they did not carry out those attacks, although its leaders have repeatedly denounced the vaccination program as a plot to sterilize people or spy on Muslims, according to a Reuters report.

Pakistan is one of just three countries in the world where polio remains endemic, the others being Nigeria and Afghanistan.