All samples from metro cities - that have tested positive for Covid - are being sent for genome sequencing, government sources said today, amid fears over an Omicron-driven third wave. In India, 18% of recently tested samples had the new variant. In Delhi, the new variant - said to be highly infectious - has been found in 50 per cent of the samples that tested positive since December 12, sources in the Health Ministry said, confirming the community spread of Omicron in the national capital.