China’s efforts to eliminate Covid-19 are coming under increasing pressure, with officials warning of a “grave challenge” in the months ahead and dozens of new cases reported over the weekend.

China’s National Health Commission on Sunday confirmed 74 new infections for the previous day, of which 50 were locally transmitted. The current wave of cases has reached the majority of the country’s 31 provinces, in the broadest outbreak since the early days of the Covid-19 pandemic last year.

The figures were released a day after officials at a press conference in Beijing said China would continue to adhere to its strict prevention measures even as other countries in the region abandoned their zero-Covid policies.

Wu Liangyou, an official at the National Health Commission, said China faced a “complex and grave challenge this winter and next spring” in controlling the virus, because the pandemic remained at elevated levels in neighbouring countries and across the world.

In China, which is hosting the Winter Olympics for the first time in February next year, new cases slowed to a trickle in mid-2020 and authorities have since then reacted swiftly to any prospect of a big outbreak.

Despite being the epicentre of the pandemic, China’s strict lockdowns and tough border controls have helped keep a tight lid on the virus.

Fewer than 5,000 people have died from the virus, according to official Chinese figures, while more than 2.3bn vaccine doses have been administered — by far the highest in the world — according to the FT’s Covid-19 vaccine tracker.

The emergence of the highly infectious Delta variant within the country, which hit the eastern city of Nanjing in July, led to stringent measures designed to limit its spread, including travel restrictions.