The first victim was Karachi's Gadap Town resident 10-month-old Omar, who had been vaccinated for the virus once before but still tested positive for the disease, health official Imran Saqib said.

The other victim was 22-month-old baby girl Hajra.

According to a local newspaper, Omar is the fourth victim from this poor locality of Gadap and fourteenth victim from the Sindh province.

Except for a two-year-old child from a village of the Sanghar district in Sindh, the rest of the 13 cases have been reported from Karachi.

In 2014 alone, Pakistan's total number of polio cases has reached 160, a sharp increase from 58 cases in 2012 and 93 in 2013.

Earlier this week, 13 new cases of polio were confirmed in a single day.

This year a total of 113 cases of polio, 27 from Khyber Pakhtunkhwa, 14 from Sindh, two from Punjab and three from Balochistan, have been reported so far from Federally Administered Tribal Areas (FATA).

Pakistan, which is already facing travel restrictions imposed by the World Health Organization, is among the three countries along with Nigeria and Afghanistan where polio virus is endemic.

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