Additionally, 824 foreigners had been, as on March 21, doing Tabligh (Chilla) activities in various parts of the country, it said.

The Home Ministry made the announcement after the headquarters of the religious sect in the Nizamuddin area emerged as one of the biggest coronavirus hotspots in India with 24 people testing positive and nearly 200 others showing symptoms.

The authorities have begun evacuating the six-storey building of some over 1,000 others believed to have been exposed to the virus.

The building belongs to the Tablighi Jamaat, a Muslim sect that hosted this month its annual congregation with attendees coming in from several nations, particularly from Indonesia, Malaysia, Thailand, Nepal, Myanmar, Bangladesh, Sri Lanka and Kyrgyzstan before they spread out to other parts of the country such as Kashmir and Andhra Pradesh creating a web of close contacts that now threatens to create an explosion of cases in the country.

"As on March 21, there were about 1,746 persons staying in Hazrat Nizamuddin Markaz. Of these, 216 were foreigners and 1,530 were Indians," the Ministry said.

The Ministry said that details of these 824 foreigners had been shared on March 21 with the sate police for identifying them, getting them medically screened and quarantined. Besides, on March 28, state police were advised to collect the names of Indian Tabligh Jamaat workers from the local coordinators to locate them on the ground. So far, the Ministry said, about 2,137 such persons have been identified in different states and they are being medically examined and quarantined.

"This process is still on and more such people would be identified and located," said the Ministry, adding it had also issued a detailed advisory to Chief Secretaries and Director Generals of Police (DGPs) of all states as well as Commissioner of Delhi Police on March 28 on this issue.

The Ministry said that state DGPs had been again advised on Monday to trace the movement of all such Tablighi workers in their area, ascertain the people coming in their contacts and take steps for their medical screening. "Many States have already started doing this."

The Ministry declared that all the Tabligh Jamaat workers staying at Hazrat Nizamuddin Markaz are being medically screened since March 26 and so far 1,203 of them have been medically screened.

Of them, 303 had symptoms of Covid-19 and were referred to different Delhi hospitals, said the Ministry, adding rest of them have been moved to different quarantine centres at Narela, Bakkarwala and Sultanpuri. "This process will continue throughout today (Tuesday) to move every Tablighi Jamaat worker out of Nizamuddin Markaz.

"It is estimated that from January 1 onwards this year, approximately 2,100 foreigners had visited India for Tablighi activities while approximately 824 of them, as on March 21, were dispersed in different parts of the country, approximately 216 of them were staying at Nizamuddin Markaz. Others might have left the country before the lockdown, it said.

It said that Tablighi Jamaat workers, both foreigners as well Indians, indulge in Chilla activities across the country throughout the year. All such foreign nationals normally report their arrival at Tablighi Markaz at Banglewali Mosque in Hazrat Nizamuddin in New Delhi.

From here, they are detailed for Chilla activities to different parts of the country. Chilla activities in all states are coordinated by district coordinators in different districts, and these in turn, in some states are supervised by state 'amirs'.

The Ministry informed that Bureau of Immigration has been sharing (since February 1) with state authorities, details of all international arrivals from affected countries based on self declaration form filled-in by them.

In addition, since March 6, Bureau of Immigration had also been sharing details of all the international arrivals (both Indians and foreigners) at all the international airports in the country to the concerned state, based on the permanent address mentioned in their passport, in case of Indians, and hotel address, in case of foreigners.