Kolkata, A total of 227 containment zone to combat Covid-19 have been created in Kolkata covering stretches in northern, central and southern parts of the city, besides the fringes, a senior state official said here on Monday.

These areas are under total lockdown, with complete restriction of people moving out or getting in from outside.

Chief Secretary Rajiva Sinha told reporters that in 18 of these containment zone, not a single case has been reported over the past two weeks.

As many as containment zones have been created in Howrah. In 13 of them, no case has been reported over the past 14 days.

In East Midnapore district, five of the eight containment zones have not reported any positive cases since April 9.

Similarly, in 13 of the 57 containment zones of 24 Parganas North district, not a sngle case has been detected in the last two weeks, said Sinha.

Kolkata, Howrah, 24 Parganas North and East Midnapore are in the four districts falling under the red zone in West Bengal.

Districts where there a large number of corona positive caseshave been detected are classified as red zones.

Sinha said the number of active Coronavirus positive cases have gone up to 504 in the state, while the death count remains 20.

"On Sunday, the number or active cases was 461. Since then, 47 positive results have been received, while four persons got discharged from hospital after having recovered fully from the disease. This takes the tally of active cases to 504," he said.

Since the outbreak of the disease, 109 patients have been discharged from hospital.

The total number of samples tested is 12,043, of which 1,150 tests were done over the past 24 hours, he said.

Sinha said the government has received 4,370 applications for opening industrial units. Of them, 2,084 have been approved, 823 are under process, while 1,463 had to be rejected as they affect containment zones.