India's health ministry warned on Sunday that a huge gathering of devotees for a Hindu festival could send coronavirus cases surging, as the country recorded the most new infections in nearly four months.
The ministry said up to 40 people were testing positive for Covid-19 daily around the site of the weeks-long Mahakumbh that began this month and peaks in April in the Himalayan holy town of Haridwar, next to the Ganges.
The festival is held only once every 12 years. Organisers have said more than 150 million visitors are expected, as many Hindus believe bathing in the river during this period absolves people of sins and bring salvation from the cycle of life and death.
In a letter to the state government of Uttarakhand, where Haridwar is located, the ministry told local authorities their daily coronavirus testing of 55,000 people in Haridwar was not enough given the large numbers of pilgrims expected, and that cases were already rising.
"This positivity rate has the potential to rapidly turn into an upsurge in cases, given the expected large footfall during Kumbh," the ministry said in a statement, citing the letter.
"Currently more than 12 states in India have shown a surge in Covid-19 cases during the past few weeks, and pilgrims expected to visit Haridwar during the Kumbh Mela could also be from these states."
Uttarakhand's government says it has made mask-wearing mandatory for devotees, would distribute millions of masks for free and also keep sanitising public areas, apart from following rules laid down by the federal government.
India reported 43,846 new coronavirus cases in the past 24 hours, with its richest state Maharashtra again accounting for about 60% of the infections.
Deaths rose by 197, the highest in more than two months, to 159,755, data from the health ministry showed.
India's new Covid-19 cases peaked at nearly 100,000 a day in September, and had been falling steadily until late last month.
But now five states - Maharashtra, Punjab, Karnataka, Gujarat and Madhya Pradesh - account for nearly 78% of the new cases. Maharashtra, home to India's financial capital Mumbai, alone reported 27,126 cases and 92 deaths.
As cases increase, Prime Minister Narendra Modi's government has been criticised for exporting more vaccines than the number of people inoculated at home so far.
Under pressure to boost local supplies, the Serum Institute of India has told Brazil, Saudi Arabia and Morocco that shipments of further doses of the AstraZeneca vaccine to them would be delayed.
India has so far donated 8 million doses and sold nearly 52 million doses to a total of 75 countries. It has administered more than 44 million doses since starting its immunisation campaign in the middle of January.