Europe has seen an increase in weekly cases of Covid-19 for the first time in months as restrictions imposed to curb the spread of the virus are eased, the World Health Organization (WHO) says. In 11 countries, which have not been named, accelerated transmission has led to "very significant" resurgences, said Regional Director Dr Hans Henri Kluge. His warnings about the risk of resurgence had become reality, he said. If left unchecked, he warned health systems would be "pushed to the brink". More than 2.6 million cases of Covid-19 and 195,000 deaths have been reported in the WHO's European region, which covers 54 countries and seven territories across Europe, the Middle East and Central Asia. Almost 20,000 new cases and more than 700 new deaths are being recorded daily. "For weeks, I have spoken about the risk of resurgence as countries adjust measures," Dr Kluge told a virtual news conference on Thursday. "In several countries across Europe, this risk has now become a reality - 30 countries have seen increases in new cumulative cases over the past two weeks. "In 11 of these countries, accelerated transmission has led to very significant resurgence that if left unchecked will push health systems to the brink once again." Dr Kluge said countries such as Poland, Germany, Spain and Israel had responded quickly to dangerous outbreaks associated with schools, coal mines, and food production settings, and brought them under control through rapid interventions. Despite warning about resurgences, he said the WHO anticipated that the situation would calm down further in the majority of countries over the summer. "But we have indeed to prepare for the fall, when Covid-19 may meet seasonal influenza, pneumonia, other diseases as well, because ultimately the virus is still actively circulating in our communities and there is no effective treatment, no effective vaccine, yet."