More than a year after the pandemic began, infections worldwide have surpassed their previous peak. The average number of coronavirus cases reported each day is now higher than it has ever been.

“Cases and deaths are continuing to increase at worrying rates,” said World Health Organization chief Tedros Adhanom Ghebreyesus on Friday.

A major reason for the increase: the ferocity of India’s second wave. The country accounts for about one in three of all new cases.

It wasn’t supposed to happen like this. Earlier this year, India appeared to be weathering the pandemic. The number of daily cases dropped below 10,000 and the government launched a vaccination drive powered by locally made vaccines.

But experts say that changes in behavior and the influence of new variants have combined to produce a tidal wave of new cases.

India is adding more than 250,000 new infections a day — and if current trends continue, that figure could soar to 500,000 within a month, said Bhramar Mukherjee, a biostatistician at the University of Michigan.

While infections are rising around the country, some places are bearing the brunt of the surge. Six states and Delhi, the nation’s capital, account for about two-thirds of new daily cases. Maharashtra, home to India’s financial hub, Mumbai, represents about a quarter of the nation’s total.