Indians struggled to register online for a mass vaccination drive set to begin this weekend as the country's toll from the coronavirus surged past 200,000 on Wednesday, worsened by shortages of hospital beds and medical oxygen.

The second wave of infections has seen at least 300,000 people test positive each day for the past week, overwhelming health facilities and crematoriums and prompting an increasingly urgent response from allies overseas sending equipment.

The last 24 hours brought 360,960 new cases for the world's largest single-day total, taking India's tally of infections to nearly 18 million. It was also the deadliest day so far, with 3,293 fatalities carrying the toll to 201,187.