ISLAMABAD - The authorities in Islamabad have sealed three more educational institutes due to spike in Covid-19 cases. According to the latest details, 23 students tested positive for the Covid-19. District Health Officer (DHO) staid that almost 50 cases have been reported in more than 24 schools/colleges in the last four days. In a bid to stop further spread of Covid-19 in schools, DHO in a letter instructed the schools/colleges to postpone all classes until further notice. DHO Dr Zaeem Zia while providing the details said that 702 individuals tested for Covid-19 in the capital against 5948 tests conducted last day. The positivity ratio in Islamabad remained 11.8% which is the highest ratio in last four months.