Doctors in India are fighting a fatal fungal infection affecting COVID-19 patients or those who have recovered from the disease, amid a coronavirus surge that has driven the country's fatalities to nearly 300,000.
The life-threatening condition, known as mucormycosis, is relatively rare but doctors suspect the sudden increase in the infection could further complicate India's fight against the pandemic.
India has reported more than 26 million cases of coronavirus overall, with almost half of those occurring in the past two months.
On Sunday, the Health Ministry reported 3741 new deaths, driving India's confirmed fatalities to 299,266.
It also reported 240,842 new infections, as daily cases remained below 300,000 for a week.
Experts say new infections in India, which had been rising steeply, may finally be slowing.
But there are some early indications that mucormycosis, also known as black fungus, is fast becoming a cause of worry.
Mucormycosis is caused by exposure to mucor mould, which is commonly found in soil, air and the nose and mucus of humans.
It spreads through the respiratory tract and erodes facial structures.
On Saturday, federal minister Sadananda Gowda said nearly 9000 cases had been reported in India so far, leading to a shortage of amphotericin B, the drug used to treat the condition.
Gowda did not share the number of fatalities, but local media have said more than 250 have died because of the disease.
Health officials were working to alleviate the drug shortage, which comes at a time when the country is already short on supplies of oxygen and other healthcare needs, Gowda said.
Mucormycosis has a high mortality rate and was already present in India before the pandemic.
It is not contagious but its frequency in the last month has left doctors shocked.
"It is a new challenge and things are looking bleak," said Ambrish Mithal, head of endocrinology and diabetes at Max Healthcare, a chain of private hospitals in India.
Mithal said the fungal infection preys on patients with weakened immune systems and underlying conditions, particularly diabetes.
Uncontrolled blood sugar can put immuno-compromised people at a higher risk of contracting the disease.
"Earlier I used to come across just a few cases every year but the current infection rate is frightening," said Mithal.
India's Health Ministry on Thursday asked states to track the spread of the condition and declare it an epidemic, making it mandatory for all medical facilities to report the cases to a federal surveillance network.
Prime Minister Narendra Modi on Friday called the disease a "new challenge".