Pakistan's faltering effort to rid the country of polio has encountered any bloody set-back after at least 12 people were killed when three roadside bombs targeted a vaccination team in the north-west. Among those killed were 11 paramilitary troops and a young boy.
Reports said the devices were detonated in Lashora, around 20 miles southwest of the city of Peshawar in Khyber Pakhtunkhwa province. While information was last night still emerging, one report said an initial explosion injured several people and that the 11 troops were killed when they went to help those hurt and a second device was set off.
Jahangir Khan, a senior official, told the AFP news agency that two vehicles belonging to the medical team were damaged in the explosions. Around a dozen people were hurt.
No-body immediately claimed responsibility for the attack. But polio workers have been repeatedly targeted and a number of militant groups have made clear their opposition to the vaccination workers. Many claim the vaccination programmes are part of a Western-backed scheme to sterilise Muslims.
Pakistan is one of just three nations where polio remains endemic and along with Afghanistan and Nigeria, huge efforts are being made to tackle the disease. India, which once suffered the most from polio, recently celebrated being three years without a confirmed case.
Violence is hampering the struggle to tackle polio. There have also been new outbreaks in Somalia and Syria.
Of the three countries where it is endemic, only Pakistan saw an increase in cases. Last year a total of 91 cases were reported, compared with 58 in 2012. The World Health Organisation said 90 per cent of Pakistan's cases were genetically linked to Peshawar.
What's more, the disease is spreading beyond Pakistan's borders. Last November, the WHO revealed that strain of polio that had broken out in Syria had originated in Pakistan.
Polio vaccination workers in Pakistan, most of them women, have been repeatedly targeted in Pakistan, apparently by the Taliban. The militants have prevented polio workers reaching large swathes of the remote tribal areas that border Afghanistan. Hundreds of thousands of youngsters have missed out on getting the vaccine.
"This is the most serious challenge for polio eradication," said Dr Rana Safdar, Pakistan's former national polio coordinator. "We used to think the problem of attacks was restricted to certain high-risk areas. But now are seeing that this can happen any where and at any time. We cannot provide security everywhere."
Suspicion about polio workers got markedly worse after the 2011 US operation to locate and kill Osama Bin Laden. In the aftermath of the operation it emerged the CIA had recruited a Pakistani doctor to organise a fake vaccination drive to try and obtain a DNA sample from the children living inside the al-Qa'ida leader's Abbottabad compound.
The doctor, Shakil Afridi, was later charged with treason and sentenced to jail for 33 years. A court has ordered a retrial and the West has been pushing Pakistan to release the doctor.