The World Health Organization said Thursday the Delta variant has led to a "surge" in coronavirus outbreaks triggering a "fourth wave" in the Eastern Mediterranean region, where vaccination rates remain low. The global health body said the highly transmissible strain, first detected in India, has been recorded in 15 out of the 22 countries of the region under its purview, stretching from Morocco to Pakistan. "The circulation of the Delta variant is fuelling the surge in Covid-19 cases and deaths in an increasing number of countries in WHO's Eastern Mediterranean Region," it said in a statement. "Most of the new cases and hospitalised patients are unvaccinated people. We are now in the fourth wave of Covid-19 across the region," said Ahmed al-Mandhari, director of WHO's Eastern Mediterranean region. Infections have increased by 55 percent, and deaths by 15 percent, in the last month compared to the month before. More than 310,000 case and 3,500 deaths have been recorded weekly. Countries such as Tunisia, which has suffered the biggest number of Covid-19 deaths in North Africa, have been struggling to contain the outbreak. Critical shortages of oxygen tanks and intensive care beds have stretched the capacities of healthcare systems regionally. WHO noted the rapid spread of the Delta variant was quickly making it "the dominant strain" in the region. According to a recent paper in the journal Virological, the amount of virus found in the first tests of patients with the Delta variant was 1,000 times higher than patients in the first wave of the virus in 2020, greatly increasing its contagiousness.