The Philippines has launched a polio immunisation campaign and declared an outbreak in the country after confirming two cases in children and finding the virus in sewage in two provinces, the country's Department of Health said.
The confirmed cases ended a 19-year period in which the country, home to about 105 million, was considered polio-free, according to the World Health Organization (WHO).
It was officially declared free of the virus, which tends to affect children under five and can cause irreversible paralysis within hours, in 2000.
The outbreak comes as the Philippines grapples with separate epidemics of measles and dengue fever that have killed more than 1,000 people, mostly children, since January.
Health officials say fears over a trial dengue fever vaccine, which health workers began administering in 2016 and then halted the following year, have caused vaccination rates for all types of viruses to plummet in recent years.
In the capital, polio vaccinations dropped from just over 77 percent of the target numbers in 2016 to below 24 percent in June, making the metropolis of 13 million a high-risk area for the re-emergence of polio, according to the Department of Health.