The number of polio cases is now all-time high in Pakistan as the country has already surpassed its own 14-year-old record of 199 cases registered in 2000.
National Institute of Health (NIH) has confirmed the four new cases.
Of the four new cases, two are from northwestern Khyber tribal region and Peshawar city and one has been traced in Sheikhupura district of Punjab, an NIH official said.
Pakistan, along with Afghanistan and Nigeria, are the only three countries in the world where polio remains endemic.
The WHO in May imposed travel restrictions on people travelling from Pakistan to other countries.
India, a polio free country, was the only nation which imposed such restriction even before the WHO took action against Pakistan.
It has declared polio certification as mandatory since January 30 for anyone applying for visa to its High Commission in Islamabad.
Pakistan has introduced polio certification counters at airports and government hospitals but people try to avoid vaccination due to long-held belief that anti-polio vaccination is a conspiracy by the west.
The ministry had issued standard operating procedures (SOPs) on May 31, asking provincial governments to implement World Health Organisation's recommendations and devise a foolproof mechanism to check the issuance of fake certificates.
