Media playback is unsupported on your device Media caption The WHO says there is currently no evidence of human-to-human transmission of the virus

The World Health Organization says there have now been five deaths in China from a new bird flu virus.

There have been 11 laboratory-confirmed cases of the H7N9 virus, a form of avian flu which had not been seen before in humans.

But the WHO says there is currently no evidence of human-to-human transmission of the virus.

Tests suggest that the virus could be treated with the anti-influenza drugs Tamiflu and Relenza.

Around 400 people who have been in close contact with the 11 cases are being monitored.

'Heightened surveillance'

The Chinese government has stepped up its disease surveillance and is retrospectively testing any recently reported cases of severe respiratory infection, to check if any cases had not been recognised as H7N9.

An inter-government task force has been formally established, and the animal health sector has intensified investigations into the possible sources of the virus.

China's government has also advised people to maintain good personal hygiene, including frequent hand-washing and avoid direct contact with sick or dead animals.

The WHO is not recommending any travel or trade restrictions.