Media playback is unsupported on your device Media caption BBC's Aleem Maqbool says a child was removed from the vehicle before the aid workers were shot dead

Seven charity workers, six of them women, have been shot dead in north-west Pakistan, police say.

The women, some of them teachers, were attacked near a children's community centre. A male colleague died with them. All were Pakistani citizens.

Their vehicle came under gunfire near the centre run by Pakistani charity Ujala, or Light.

Militants targeting a vaccination programme are suspected. No group has said it carried out the attack.

The incident happened in the Swabi district close to a road connecting Peshawar to the eastern city of Lahore.

The centre was part school and part clinic, specialising in maternal health.

"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 AFP.

He added that the driver of the vehicle had also been injured in the attack, which took place near a motorway junction.

The BBC's Aleem Maqbool, in Islamabad, says that, according to police, this is the first such attack on NGO workers in the area.

Our correspondent says that those running the centre said they suspect its vaccination programme was the reason it was attacked.

Of the seven people who were killed, two were health workers and five were teachers.

Last month, in a series of attacks, gunmen killed nine health workers taking part in a national polio vaccination drive.

While the Pakistani Taliban have denied carrying out the killings, they have long denounced the vaccination drive as a Western plot either to gather intelligence or to sterilise Muslim children.

The killings prompted the UN children's agency and the World Health Organisation to suspend work on polio campaigns in the country.