The World Health Organization (WHO) said Thursday that Yemen has been polio-free since 2006,

All cases of acute flaccid paralysis examined from 2018 to 2019 are negative for poliovirus, the UN said on its Twitter account.

On World Polio Day, WHO said it was on high alert, with hundreds of suspected cases being investigated in Yemen each year.

Late last year, WHO and UNICEF launched a polio vaccination campaign, targeting more than 5 million children under the age of five in various provinces of the country.