Four more people have died from a new strain of bird flu in China, bringing the death toll from the H7N9 virus to 36 from 131 confirmed cases, the World Health Organisation (WHO) has said.
The United Nations health agency said a written statement on Friday that the four deaths were from cases that had already been identified in laboratories.
It said here had been no new cases of infection with H7N9 Since May 8.
The WHO reiterated that there was no evidence that the new strain of bird flu, which was first detected in patients in China in March, was passing easily from human to human. If such a feature emerged it could spark a pandemic.
But it said: "Until the source of infection has been identified and controlled, it is expected that there will be further cases of human infection with the virus."
Nine labs open
The WHO said that Chinese health authorities had continued with enhanced surveillance, epidemiological investigations, close contact tracing, clinical management, laboratory testing and sharing of samples as well as prevention and control measures.
The number of new cases has dwindled in some provinces and operations
"In the past week, the Shanghai and Zhejiang provincial governments have started to normalise their emergency operations into their routine surveillance and response activities," the health organisation said.
Meanwhile, Saudi Arabia has said that it has dedicated nine extra laboratories to help investigators track a deadly new respiratory virus related to SARS that appears to be centred in the kingdom.
The Health Ministry announcement on Thursday follows its report that two health care workers became ill this month after being exposed to patients with the virus.
Experts were closely studying whether it could spread easily from person to person.
The WHO had been informed of 40 confirmed cases of the virus since September 2012, mostly in Saudi Arabia but also in Europe and Jordan.
At least 20 people have died, including 15 reportedly in Saudi Arabia.
The virus has been compared to SARS, a pneumonia that surfaced in China in late 2002 and killed at least 774 people worldwide.
The WHO, which is closely monitoring the viruses, has said that the bird flu and SARS-like viruses had the potential to cause a global pandemic if they evolved into a form easily spread between people.