Another central team will arrive in Calcutta soon as the Union health ministry is sending 20 public health teams to as many districts across the country reporting the highest number of Covid-19 cases, a release by the Centre’s Press Information Bureau (PIB) said late on Sunday.

The new team will only be a “public health team”, according to the release that did not reveal the strength or composition of the public health team.

The team will “support the States in implementation of containment measures within these districts, cities”.

Bengal chief secretary Rajiva Sinha had said on Thursday that there were 264 containment zones in Calcutta out of 444 such zones in all states. Containment zones are localities or neighbourhoods from where Covid-19 cases have been reported.

Neighbourhoods from where cases were reported long ago and no new case has been reported in 21 days are not considered containment zones, a corporation official of said.

State government officials said about 500 cases have been reported from Calcutta so far.

The earlier central team that split into two groups and went to north and south Bengal had alleged lacunae in the state’s Covid testing and reporting mechanism.

The inter-ministerial teams headed by additional secretary rank officers of the Centre and members National Disaster Management Authority, department of consumer affairs and a public health specialist.

It was not immediately clear whether the team, whose formation was announced on Sunday, will have only public health specialists.

The 20 districts the team will visit account for 68 per cent of coronavirus disease patients in hospitals and 70 per cent of Covid-19 deaths.

Public health officials have determined that in eight of these districts — Ahmadabad, Mumbai, Chennai, Central Delhi, Calcutta, North Delhi, Kanpur Nagar, Krishna — the doubling time for the total number of infections is faster than 10 days.

The ministry said the high doubling rates could be because of poor physical distancing measures, ineffective contact tracing, or large proportions of Covid-19 positive cases among healthcare workers.

Field units in such districts would need to verify physical distancing and perimeter control in the containment zones, ensure rigorous contact tracing and determine that healthcare workers have access to protective gear and hydroxychloroquine, the ministry said.