States across India have ordered emergency measures to counter a surge of the rare, often deadly, "black fungus" infection among Covid-19 patients.
Two more states declared epidemics of mucormycosis while New Delhi and other major cities opened special wards to treat thousands of cases of the infection commonly known as black fungus.
India normally deals with fewer than 20 cases a year, but the infection has become a new threat after a second wave of Covid-19 that killed 120,000 people in six weeks.
The health ministry on Friday reported another 4,209 deaths and 259,551 new infections over the previous 24 hours, raising India's death toll to 291,331 out of 26.03 million cases.
The fungal infection, which some doctors blame on the high use of steroids in treating coronavirus patients, kills more than 50 per cent of sufferers within days. In some cases, surgeons removed eyes and upper jaws to save lives.
Authorities have not said how many people have died from black fungus.
But a government alert to state authorities on Thursday said teams of reconstruction and general surgeons as well as ear, nose and throat specialists had to be readied to treat the growing number of sufferers.
Gujarat and Telangana states became the latest to declare black fungus epidemics on Thursday, a day after Rajasthan.
Maharashtra state has reported more than 2,000 cases. Gujarat, home state of Prime Minister Narendra Modi, has about 1,200, officials said.
Ahmedabad civil hospital, one of Gujarat's biggest, was treating 371 cases, a spokesman said. Health officials said there were about 400 cases in the government hospital in the city of Rajkot.
New Delhi set up special wards at three hospitals to cope with increased numbers of black fungus.
There are more than 200 black fungus patients in New Delhi hospitals, with dozens on waiting lists for beds, according to media reports.
The IT hub of Bangalore opened special wards on Wednesday which filled within hours, doctors said.
Anti-fungal drugs are the latest shortage to hit India's stretched healthcare system and social media is being flooded with requests from relatives of mucormycosis patients pleading for help to find medicine.
Black fungus is caused by organisms called mucormycetes, which can enter the body through breathing or skin injuries.
These are naturally present in soil and decaying organic matter, but once inside the human body, they can infect air pockets behind the forehead, nose, cheekbones and between the eyes and teeth.
Some doctors said the panic use of steroids to combat Covid-19 helped the spread of black fungus.
"Indiscriminate use of steroids to treat Covid-19 patients should be avoided," Maharashtra's Health Minister Rajesh Tope said Wednesday.
Other doctors say the unhygienic conditions in some hospitals when putting coronavirus patients on oxygen cylinders allowed black fungus to take hold.
Coronavirus patients with diabetes and a weakened immune system are particularly prone to attack.
Many of the drugs used to fight the coronavirus suppress the body's immune system that would normally ward off a fungal infection.