India told state governments to be proactive and on the lookout for surges of the Omicron coronavirus variant after cases nearly doubled within a week across a dozen states.

India, whose already creaking health system became overwhelmed by Covid-19 cases in the summer, has recorded 200 Omicron infections, mostly in the western state of Maharashtra and the nation's capital New Delhi, the health ministry said.

Health Secretary Rajesh Bhushan said states could take containment measures including night curfews and allow fewer people at offices and on public transport should there be a surge.

States were allowed to impose restrictions if the rate of new infections reached 10 per cent or higher in a week or 40pc of oxygen or ICU beds were occupied, Reuters reported.