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NEW DELHI — Authorities have quarantined at least 40,000 people in the Indian state of Punjab following a coronavirus outbreak linked to a single Sikh priest.

Baldev Singh, 70, had transferred in an Italian airport before returning home from a visit to Germany, a public relations officer in the Shaheed Bhagat Singh Nagar district told NBC News.

After returning to his home village of Pathwala, where he was a priest at the gurdwara, or temple, Singh ignored advice to self-isolate and attended several religious gatherings.

Then he traveled to the Hola Mohalla festival with two friends in the nearby city of Anandpur Sahib. The festival, held from March 10 to March 12, draws around 300,000 people each day. They camp out and enjoy mock battles, music and poetry, as well as large communal kitchens.

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Swapan Sharma, senior superintendent of police in Rupnagar, said crowds were down by about 50 percent this year as people had been warned not to attend religious and social gatherings.

Singh died shortly after he attended the festival on March 18, and tests revealed that the coronavirus killed him. A number of his relatives have also tested positive.

Vinay Bublani, the district magistrate in Shaheed Bhagat Singh Nagar, where Singh's village is based, said authorities had identified 650 people who were in contact with Singh. They were being tested, he added.

Authorities have also quarantined around 20 villages in the region, totaling about 40,000 people, to stop the virus from spreading. Officials have been going door to door to inspect people showing symptoms.

Indian Prime Minister Narendra Modi ordered a lockdown of the country of 1.3 billion people for 21 days on Wednesday. Only those shopping for food or medicine are officially allowed out.

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To date, 19 people have died from coronavirus in the country, and 819 people have tested positive. However, the country has one of the lowest testing rates in the world.

Sikh temples including the famous Golden Temple — the holiest and most important pilgrimage site in Sikhism — remain open.

The Shiromani Gurdwara Parbandhak Committee, which manages and runs the Golden Temple in the city of Amritsar, said it would not close.

"We cannot shut our doors and stop people from coming to the spiritual center for Sikh faith," President Gobind Singh Longowal told NBC News, adding that numbers were down because of the coronavirus outbreak.