India has recorded its highest daily coronavirus death toll since the pandemic began – a day after it became the first country to see more than 400,000 new cases.
Its health ministry said 3,689 people had died within the past 24 hours.
Prime Minister Narendra Modi met the health minister on Sunday morning to review the crisis.
Hospitals are battling to treat patients amid a chronic shortage of beds and medical oxygen.
Amid the crisis, vote counting started on Sunday for elections held in five states in March and April.
The outcomes will be watched for signs of how the pandemic has affected support for Mr Modi and his Hindu nationalist party, the BJP.