|Read more pictures|
Gunmen shot dead six health workers on an anti-polio drive in a string of attacks in Pakistan over 24 hours, officials said on Tuesday, raising fears for the future of efforts to eradicate the crippling disease in one of its last strongholds.
It was not clear who was behind the shootings but Taliban insurgents have repeatedly denounced the vaccination campaign, which aims to wipe out polio in one of the last three countries where it is endemic, as a Western plot.
"Such attacks deprive Pakistani's most vulnerable population - especially children - of basic life-saving health interventions," the World Health Organisation and the U.N. Children's Fund (UNICEF), which are working with the Pakistani government on the campaign, said in a joint statement.
Health officials suspended the campaign in two provinces of Pakistan, Sindh and Khyber Pakhtunkhwa. Karachi, the capital of Sindh, is Pakistan's biggest city and home to 18 million people.
Four people were killed in separate attacks on health workers in Karachi on Tuesday, said the United Nations. Another health worker was killed in the same city on Monday.
The team had received telephone calls warning workers they would regret helping the "infidel" campaign against polio, said health official Gul Naz, who oversees the project in the area where the four women were shot.
In the northwestern city of Peshawar, gunmen on a motorbike shot a 17-year-old girl supervising an anti-polio campaign, said government official Javed Marwar.
This is simple tips to earn money online