India has ordered stricter surveillance of a rare fungal disease affecting COVID-19 patients, authorities have announced.
Delhi will also set up special hospital wards to combat mucormycosis, or "black fungus," authorities added.
Maharashtra, one of the states worst hit in the second wave of coronavirus infections, has reported more than 2,000 cases of mucormycosis.
Rajasthan and Telangana states, meanwhile, have declared "black fungus" epidemics.
The emergence of the disease piles even more pressure on hospitals already battling with the world's highest number of daily COVID-19 infections.
Who is at risk of 'black fungus'?
Coronavirus patients with a weakened immune system and diabetes are particularly prone to mucormycosis.
In a letter to state governments, Health Secretary Lav Agarwal said mucormycosis had emerged as India's new challenge for COVID-19 patients on steroid therapy and those with pre-existing diabetes.
Agarwal called on state governments to declare it as a "notifiable disease" under the Epidemics Act, meaning state authorities must identify and track every case.
What are the symptoms of 'black fungus'?
The disease has been dubbed "black fungus" because it causes blackening or discoloration over the nose.
The disease can also cause blurred or double vision, chest pain, breathing difficulties and coughing blood.
Some doctors say strong steroids used to treat severe COVID-19 can reduce immunity and increase sugar levels, thereby helping the spread of "black fungus."
Many drugs used to fight COVID-19 suppress the body's immune system that would normally protect the individual from a fungal infection.
The disease kills more than 50% of patients within days and, in some cases, surgeons have removed eyes and upper jaws to prevent the spread of the disease.
India COVID-19 cases continue to soar
India on Friday reported 2,59,591 new coronavirus infections over the previous 24 hours. The number of deaths surged by 4,209 overnight, taking the total tally to 2,91,331.
India's coronavirus caseload stands at 2,60,31,991, the world's second-highest after the US. Some health experts warn infections and deaths could be five to 10 times higher.