KARACHI: The emergency operations centre (EOC) for polio in Sindh has launched investigations into the causes of emergence of two more polio cases in the city, which increased the number of polio victims to four in Karachi and nine in the province over the past two months, officials said on Tuesday.

The authorities confirmed two more cases of polio in Gadap union councils ñve and six.

Both the children belonged to the Pakhtun families. One of them was identified as 22-month-old Mudassir, a son of Khanzada Khan, a resident of UC-5, Gadap.

Officials said the infection had affected both legs of the child. He had received no doses in routine immunisation campaigns, but they added that four times in the past he had been administered with the boosters in special campaigns.

The other child, 47-month-old Shayan, son of Shahid Alam, was living in UC-6 of Gadap. The deadly disease affected the child`s right leg, although he was inoculated against the disease seven times previously.

The number of polio cases in Karachi climbed to four in fewer than two months. The rest of five cases in Sindh were reported from Dadu (2), Qambar (1), Sukkur (1), and Khairpur (1).

Officials in the provincial health ministry said the confirmation of polio cases had left them worried as both the children, despite hailing from conservative families, had received polio vaccines, yet they could not be saved from the crippling virus.

`Most probably their bodies would have little immunity to resist against the virus and assist the vaccine, which eventually led to the tragedy,` said an official.

`This is extremely unfortunate as this is becoming a bad end to an otherwise good year in which we have seen a significant drop in polio cases,` said an EOC official.

The ECO ofñcial said they had been expressing concern earlier that despite vaccinating children, there had been persistence of the polio virus in environment which inevitably resulted in polio cases.

The ofñeials said they had devised a strategy tointerrupt the virus circulation and the next six months were critical.

`The essence of this strategy is ruthless accountability, an honest re-assessment of security provision and ensuring its deployment, strengthening the functionality of the provincial EOC and district polio control rooms and strengthening work in high-risk union councils through further involving the communities,` said an official.

Meanwhile, Health Minister Jam Mehtab Dahar on Tuesday asked the chiefsecretary ofSindh to provide additional police force for security of polio teams in Karachi.