22 kids have died of measles in Pakistan's Sindh province in a month, say officials.
Four children aged between three and six years died in Sukkur district Monday, the Dawn reported Tuesday.
Senior officials have rushed to the region following reports that measles was spreading to Larkana, Kandhkot-Kashmore and Jacobabad.
Federal Minister for Religious Affairs Syed Khursheed Shah blamed the spread of the disease to "lethargy" of the health officials and rejected a report that most deaths occurred due to cold weather.
Officials said a vaccination team would visit door-to-door in the affected villages Tuesday to provide medical treatment to the children.
Around 4.2 million children aged nine months to 10 years would be vaccinated against measles in 11 districts.
Iqbal Memon, president of the Pakistan Paediatric Association, said over 300 outbreaks of measles have been reported this year against 66 in 2011. More than 100 children have lost their lives to measles in 2012.