ISLAMABAD, May 30 (Xinhua) -- Two environmental samples collected from Pakistan's northwest Khyber Pakhtunkhwa province have tested positive for wild poliovirus, the Pakistani Health Ministry said on Monday.

Wild poliovirus type 1 has been found in sewage samples collected from Naray Khuwar and Larama collection sites of the Peshawar district on May 9 and May 16, respectively, the ministry said in a statement.

The isolated viruses are genetically linked to the virus cluster circulating in Afghanistan's eastern Nangarhar province, it added.

As the only two endemic countries, Pakistan and Afghanistan are united in their fight against polio and both countries would not rest until they eradicate it, Pakistani Health Minister Abdul Qadir Patel was quoted as saying in a statement.