India's Covid-19 death tally surged by a record 6,148 fatalities on Thursday as the eastern state of Bihar reported numbers about 72 per cent higher than its previous recorded toll. The new figures confirm that the devastation across the nation is far worse than official data show. Bihar’s health department on Wednesday said Covid-19 had killed 9,429 people in the state, nearly double its previous count. Authorities did not specify when the deaths occurred. Patna district, where the capital is located, reported the highest number of deaths at 862, according to a statement posted on the government's Twitter account. The Patna High Court last month expressed concern about inconsistency in the death toll presented by government officials in separate affidavits, the <em>Hindu</em> newspaper reported. Experts believe that India’s case and fatality figures are vastly under-counted, especially in rural areas where record-keeping is patchy. Data revisions throughout the pandemic are relatively common, with places from the US to Spain, China and Turkey adjusting their numbers for reasons such as lags in hospital reporting and people dying at home before a Covid-19 diagnosis was made. Peru last week more than doubled its death toll, and India’s financial hub Mumbai raised its tally last year citing technical glitches in recording data. India has reported nearly 20 million Covid cases in 2021, compared with 10.3 million last year, driven by the Delta variant that is more transmissible than other new strains. The strain is linked to more severe symptoms and a higher risk of hospital admission. While new daily infections and deaths have fallen from their peaks, India is still struggling to curb the spread of the virus and accelerate the pace of vaccination to guard against the next wave.