Two more people have died in China from a new strain of bird flu, raising the death toll from the virus to 13, state media reported Sunday.

The official Xinhua News Agency said the two deaths were reported in Shanghai and that three new cases were also confirmed in the financial hub. A total of 11 new cases were reported Sunday — including two in a central province that previously had been unaffected. In all, 60 cases of the virus, known as H7N9, have been reported in China.

INTERACTIVE: Tracking the new strain of bird flu

.A World Health Organization official said Sunday that it wasn't surprising that the virus had spread to Beijing.

Michael O'Leary, head of WHO's office in China, said it's not the case that everyone confirmed to be infected with H7N9 was "clustered in one small area with the same source of exposure."

"So we've been expecting new cases to occur. ... Furthermore, we still expect that there will be other cases," he said.

Four new cases were reported Sunday in eastern Zhejiang province and two more in Jiangsu.

Health officials believe the virus, which was first spotted in humans last month, is spreading through direct contact with infected fowl.

O'Leary said "the good news" was that there was still no evidence that humans had passed on the virus to other humans.

"As far as we know, all the cases are individually infected in a sporadic and not connected way," he said, adding that the source of infection was still being investigated.

Beijing girl improving

The girl from Beijing, whose parents are in the live poultry trade, was admitted to a hospital Thursday with symptoms of fever, sore throat, coughing and headache, the Beijing Health Bureau said.

O'Leary said early treatment can be effective, as demonstrated by the girl, who was in stable condition.

In the only other reported cases outside of eastern China, health officials in Henan province said tests on two men Thursday had later revealed they had the virus.

They said a 34-year-old restaurant chef who had displayed flu symptoms for about a week was in critical condition in a hospital, while a 65-year-old farmer who was in frequent contact with poultry was in stable condition after receiving treatment.

They said 19 people who had been in close contact with the two men did not show any flu symptoms.

China has been more open in its response to the new virus than it was a decade ago with an outbreak of SARS, when authorities were highly criticized for not releasing information.