More than 25,000 children were rushed to hospital in northwest Pakistan after the spread of unfounded rumours that a polio vaccine led to fainting and vomiting.
The scare, which travelled widely online, followed inaccurate reports that students attending a private school in a village near Peshawar fell sick after receiving their polio drops.
Many residents of the region have long been suspicious of the vaccine with local militants and extremists claiming it is a Western conspiracy to harm or sterilise children.
After hearing speculation that students had fallen ill during the three-day immunisation campaign, local mosques used their loudspeakers to warn parents against their children receiving the vaccine.
A scaremongering Twitter video was also published where a man instructed local children to faint because they had been “poisoned” by the drops.
Panic quickly turned to anger and a mob of around 500 people set fire to a local health care centre. There were no reports of injuries.
Authorities in the province of Khyber Pakhtunkhwa did little to dampen fears, instead declaring an emergency at major hospitals in three provincial districts.
Concerned parents then rushed their children to hospitals despite them suffering no side effects, according to an AFP reporter in the city of Peshawar.