Five female health workers involved in a vaccination programme to eradicate polio have been shot dead in Pakistan.
The coordinated attacks claimed the lives of four close to Karachi and one in Peshawer.
The murders have forced the UN immunisation programme in Karachi to be suspended.
No group has claimed responsibility for the killings, but the Taliban has denounced the programme as a Western plot.
Gul Naz Nigat, a health offical involved in the programme, said: “I was told around noon that two of my team had been shot. I checked one team they said they were OK. Then I called another and no one answered the call. I was worried, but I got to them,” she said.
A male first aider working on the programme was killed in Karachi on Monday.
Opposition to such campaigns in Pakistan is not uncommon after a fake CIA hepatitis vaccination programme helped locate Osama Bin Laden.
The Pakistani government has declared polio a national emergency and hopes to vaccinate some 33 million children.
Prime Minister Raja Pervez Ashraf condemned the attacks.
Polio is endemic in only three countries Pakistan, Afghanistan and Nigeria.