Coronavirus: People from Malaysia, Indonesia, Saudi Arabia and Kyrgyzstan attended the event.

Highlights Over 2,000 people attended the congregation

More than 300 people taken to different hospitals to be tested in Delhi

Nine attendees have tested positive in the Andaman and Nicobar islands

Six people who attended a congregation at a mosque in Delhi's Nizamuddin have died in Telangana after testing positive for coronavirus. A cleric at the event had died in Srinagar last week.

More than 2,000 delegates, including from Malaysia, Indonesia, Saudi Arabia and Kyrgyzstan, attended the congregation in mid-March of Tabligh-e-Jamaat - a Muslim religious organisation.

In a huge health risk, as many as 1,400 people continued to stay at the Jamaat's "Markaj" even after this period even as a 21-day nationwide lockdown was imposed on March 24.

Over 300 people who were part of the congregation have been taken to different hospitals to be tested for coronavirus in Delhi and kept in isolation.

Nine attendees and the wife of one of them have tested positive in the Andaman and Nicobar islands.

Of the six people in Telangana, two died in Gandhi Hospital, one each in Apollo Hospital, Global Hospital, in Nizamabad and in Gadwal.

Special teams have identified those who came in contact with these people and they have been shifted to hospitals, a note from Chief Minister KCR's office said, adding that they have been tested and are being treated.

The authorities have appealed to all those who participated in the congregation to contact officials. At least 10 Indonesians who went to Telangana after the event tested positive.

Delhi Police, Central Reserve Police Force (CRPF) officials and medical teams went to the South Delhi locality late on Sunday night after reports said a large number of people were showing symptoms for the disease.

The area has been virtually sealed over fears that some people may have contracted the virus.

Chief Minister Arvind Kejriwal has ordered a First Information Report or FIR against the cleric who was leading the congregation.

The police said they have been trying to convince the organisers to vacate the building since March 24 but the attendees said many had been stranded there because of the nationwide lockdown.

Authorities zeroed in on the shrine complex after it was found to be the common factor between a patient who died in Srinagar and 11 Indonesians who tested positive in Telangana.

Among those staying in the facility's six-floor dormitory are about 280 foreigners, the police said.

Worryingly, many of the visitors travelled all over India after the event. After the gathering, they dispersed in 20-30 buses.

The police have reported the potentially grave situation to the home ministry, the sources said. Nearly 30,000 people live in Nizamuddin west and Nizamuddin Basti area, news agency PTI said.

In the worst-case scenario, this could lead to a huge jump in coronavirus cases in Delhi. There are over 1,200 cases in the country, including 32 deaths.