British Education Secretary Gavin Williamson on Thursday did not rule out a rise in coronavirus infections being caused by children going back to classrooms, as hundreds of thousands of pupils in England and Wales are returning to classrooms this week. "This is why we"re doing the testing program and we"re encouraging children to take part in it, parents, and of course teachers and support staff as well," Williamson told Sky News. He said children must return to a "normal pre-pandemic" experience in schools, despite the risk of an increase in COVID-19 cases. "We"re trying to strike that constant, sensible balance of actually giving children as normal experience in the classroom as possible, but also recognizing we"re still dealing with a global pandemic," he said. There is capacity to both give vaccinations to 12 to 15-year-olds and deliver a booster program while other measures could be introduced if necessary, he said, without explaining what further measures might include. He insisted the British government was "absolutely clear it wanted to avoid" a return to bubbles in schools and whole classes and year groups being sent home due to outbreaks of infection. Scientists warned that the increased mixing related to reopening schools, combined with reduced health and safety rules, could lead to a rapid raise in cases throughout September. In Scotland, COVID-19 cases among young people have risen sharply since schools reopened and restrictions were dropped two weeks ago. Experts have warned that it is "highly likely" there will be large levels of infection in schools across the country by the end of September. More than 88 percent of people aged 16 and over in Britain have had their first dose of vaccine and nearly 79 percent have received both doses, the latest figures showed. To bring life back to normal, countries such as Britain, China, Germany, Russia and the United States have been racing against time to roll out coronavirus vaccines. — Agencies