People wear masks as they cross a street during evening rush hour, as the country is hit by an outbreak of the novel coronavirus, in Beijing, China, March 3, 2020.

A Chinese company says it has developed the country's first facial recognition technology that can identify people when they are wearing a mask, as most are these days because of the coronavirus, and help in the fight against the disease.

China employs some of the world's most sophisticated systems of electronic surveillance, including facial recognition.

But the coronavirus, which emerged in Hubei province late last year, has resulted in almost everyone wearing a surgical mask outdoors in the hope of warding off the virus - posing a particular problem for surveillance.

Now Hanwang Technology Ltd, which also goes by the English name Hanvon, said it has come up technology that can successfully recognize people even when they are wearing masks.

"If connected to a temperature sensor, it can measure body temperature while identifying the person's name, and then the system would process the result, say, if it detects a temperature over 38 degrees," Hanwang Vice President Huang Lei told Reuters in an interview.

The Beijing-based firm said a team of 20 staff used core technology developed over the past 10 years, a sample database of about 6 million unmasked faces and a much smaller database of masked faces, to develop the technology,

The team began work on the system in January, as the coronavirus outbreak gathered pace, and began rolling it out to the market after just a month.

It sells two main types of products that use the technology. One performs "single channel" recognition that is best used at, for example, entrances to office buildings.

The other, more powerful, product is a "multi-channel" recognition system that uses "multiple surveillance cameras".

It can identify everyone in a crowd of up to 30 people "within a second", Huang says.

"When wearing a mask, the recognition rate can reach about 95%, which can ensure that most people can be identified," Huang said, adding the success rate for people without mask is about 99.5%.