New Delhi, Two days after the nationwide lockdown was extended, the Central Government has released a list of 170 hotspot districts, which includes all six metros and various other large cities. The list includes all nine districts of national capital.

According to the government, any hotspot called as a red zone would be a district or city that contributes to more than 80 per cent of the cases in the country or the state. Besides, places that show a high rate of infection that has a doubling rate of less than four days -- will also be tagged in this category.

According to the list, there are 207 other districts marked as potential hotspots and the government has tasked the states to ensure the containment of outbreak in these regions.

The only way that a district or region can be brought out of the red zone is when there is no new case of COVID-19 for at least 28 continuous days, and once this is achieved, the district would be called green zone -- COVID-19 free area.

Union Health Secretary Preeti Sudan also wrote to chief secretaries of states and Union territories, asking them to divide their states and UTs into two sections -- hotspot and non-hotspot areas.

The states also need to identify hotspots based on doubling rate of confirmed cases. The exercise of identification of hotspots, she says, has to be done on a weekly basis, every Monday.

She has advised strict containment plans for such clusters. Segregating areas into three zones, she said, "Containment operation would be deemed over when there is no case reported in 28 days from an area after the last case tests negative. Hotspots (designated red zones) will be assumed to be undertaking effective containment activities, if no case is reported in the next 14 days (designated orange zones) and will be deemed successful in containment, if no case is reported for 28 days (designated green zones).