Some 900 million people in China have been infected with coronavirus as of January 11, according to a study by Peking University, media reports said.

The report estimates that 64 per cent of the country's population has the virus, BBC said.

It ranks Gansu province, where 91 per cent of the people are reported to be infected, at the top, followed by Yunnan (84 per cent) and and Qinghai (80 per cent).

A top Chinese epidemiologist has also warned that cases will surge in rural China over the lunar new year.

The peak of China's Covid wave is expected to last two to three months, added Zeng Guang, ex-head of the Chinese Center for Disease Control.

Hundreds of millions of Chinese are travelling to their hometowns - many for the first time since the pandemic began - ahead of the lunar new year on January 23.

China has stopped providing daily Covid statistics since abandoning zero Covid.

But hospitals in big cities - where healthcare facilities are better and more easily accessible - have become crowded with Covid patients as the virus has spread through the country, BBC reported.

At an event earlier this month, Zeng said it was "time to focus on the rural areas", in remarks reported in the Caixin news outlet.

Many elderly, sick and disabled in the countryside were already being left behind in terms of Covid treatment, he added.

China's central Henan province is the only province to have given details of infection rates - earlier this month a health official there said nearly 90 per cent of the population had had Covid, with similar rates seen in urban and rural areas.

However government officials say many provinces and cities have passed the peak of infections.

The Lunar New Year holidays in China, which officially start from January 21, involves the world's largest annual migration of people, BBC reported.

Some two billion trips are expected to be made in total and tens of millions of people have already travelled. (SJ/IANS)