Three workers in a polio eradication campaign were shot in Pakistan on Wednesday, and two of them were killed, the latest in an unprecedented string of attacks over the past three days that has partially halted the UN-backed campaign.

The United Nations in Pakistan has pulled all staff involved in the campaign off the streets.

The government said immunisation was continuing in some areas without UN support although many workers refused to go out. Women health workers held protests in Karachi and Islamabad. – Photos by AFP, AP and Reuters