India has reported its biggest single-day increase in coronavirus cases as officials raced to track down some 9,000 people exposed to the country's biggest infection cluster during a Muslim missionary group's gathering in the capital last month, according to Reuters.

The number of cases jumped on wednesday fuelled by infections among people who either attended prayers and lectures at the Tableeghi Jamaat's headquarters in a packed densely-packed Delhi neighbourhood or came into contact with them later. A government official said about 9,000 people were unaccounted for, of which 2,000 were identified as officials of the Tableeghi and the rest were described as primary contacts.