Over 2,000 delegates, including from Indonesia and Malaysia, attended the Tabligh-e-Jamaat congregation in Nizamuddin West from March 1-15, officials said on March 30 as the south Delhi neighbourhood was virtually sealed following fears that some people may have contracted COVID-19.
Delhi Police and CRPF officials and medical teams went to the locality late on Sunday night after reports that a large number of people were showing symptoms of the disease, the officials said.
At least 100 people were also tested for the disease. The results are expected on March 31.
The entire area, which includes residences and the headquarters of the Tabligh-e-Jamaat, a Muslim religious organisation, was virtually cut off.
The joint Delhi Police-CRPF-medical team has been checking people and shifting them to designated hospitals for quarantining, the officials said.
Alarm bells started ringing after a man in his 60s who had attended the congregation succumbed to COVID-19 in Srinagar last week.
According to officials, there were several smaller congregations culminating in the big meeting at the headquarters of the organisation, which shares its wall with the Nizamuddin police station and is adjacent to the famous shrine of Khwaja Nizamuddin Auliya.
The congregation was attended by preachers from several countries, including Saudi Arabia, Indonesia, Dubai, Uzbekistan and Malaysia. About 600 Indians from different parts of the country also participated.
The Indian members of the group left on trains and flights. Contacts of a few cases that were identified in several parts of the country were traced to the congregation, the officials said.
Buses have been kept in readiness for shifting people to quarantine centres. Hotels in the area that had housed people from the congregation have been sealed. On March 24, Prime Minister Narendra Modi announced a 21-day nationwide lockdown to curtail the spread of the disease.
Delhi Police has been using drones for surveillance to check any violations in the area.