Mortality among young, mid-age group is a cause of concern: Karnataka Health Minister K Sudhakar on Tuesday expressed concern over mortality among the young and mid-age groups due to COVID-19, amid a spike in cases, and has sought for a death audit from expert doctors to know the reasons.He also said the second wave of the pandemic was spreading faster than the first wave.Meanwhile, the Union Health Ministry on Tuesday said that next four weeks are very critical for India in controlling the resurgence of covid-19 cases.