Photo/Illutration Medical staff work in the negative-pressure isolation ward in Jinyintan Hospital, designated for critical COVID-19 patients, in Wuhan in central China's Hubei province on Feb. 13. (Chinatopix Via AP)

BEIJING--A new coronavirus has taken a growing toll of Chinese health workers on the front line of the fight to stop it, a top official said on Friday, as authorities reported more than 5,000 new cases, including more than 120 deaths.

Policymakers pledged to do more to stimulate economies hit by the virus, helping Asian stock markets edge higher, with Chinese shares headed for their first weekly gain in four.

China's National Health Commission said it had recorded 121 new deaths and 5,090 new coronavirus cases on the mainland on Thursday, taking the total number of infected to 63,851.

Some 55,748 people are being treated, while 1,380 people have died of the virus that emerged in December in Wuhan, capital of the central province of Hubei.

The latest toll takes account of some deaths that had been double counted in Hubei, the commission said.

The Chinese health commission vice minister, Zeng Yixin, said 1,716 health workers had been infected and six had died as of Tuesday, with the number of infected staff rising.

"The duties of medical workers at the front are indeed extremely heavy; their working and resting circumstances are limited, the psychological pressures are great, and the risk of infection is high," Zeng told a news conference.

Chinese officials and hospitals have repeatedly spoken of a shortage of protective equipment, including face masks.

The new figures for total infections gave no sign the outbreak was nearing a peak, said Adam Kamradt-Scott, an infectious diseases expert at the Centre for International Security Studies at the University of Sydney.

"While the Chinese authorities are doing their best to prevent the spread of the coronavirus, the fairly drastic measures they have implemented to date would appear to have been too little, too late," he said.

Chinese scientists are testing two antiviral drugs and preliminary results are due in weeks, while the head of a Wuhan hospital said plasma infusions from recovered patients had shown some encouraging preliminary results.