The death toll in China from the coronavirus epidemic rose to 2,233 on Friday after 115 more people died in Hubei province, the hard-hit epicentre of the outbreak.

The vast majority of the deaths were in the provincial capital of Wuhan, where the virus first emerged in December, according to a daily update from the Hubei health commission.

Around 75,000 people have been infected by the new coronavirus in China, and hundreds more in over 25 countries.

The Hubei health commission said there were 411 new cases of the virus in the province, with 319 in Wuhan and the rest spread out across several other cities.

China said on Thursday that it had once again changed the method of counting patients with the novel coronavirus and will now include only those diagnosed by laboratory tests.

It was the second revision of criteria in just eight days, a move that could muddle statistics and complicate efforts to track the spread of the illness.

Chinese health officials had last week said that patients from Hubei who had been diagnosed through clinical methods including lung imaging would be added to the count in addition to those confirmed by lab tests.

That led to a huge one-day increase in the number of confirmed cases — 14,840 — on February 13.

The change was blamed on a backlog of patients awaiting nucleic acid tests whose condition was deteriorating and needed urgent treatment.

National figures on the virus are typically released hours after Hubei's numbers.