PHNOM PENH: As China scrambles to contain a deadly new strain of bird flu, Cambodia is battling a spike in the better known H5N1 strain that is baffling experts a decade after a major outbreak began in Asia.

Bird flu has killed eight people so far this year in Cambodia, including six children, while more than 13,000 chickens have been culled or died from the highly contagious illness.

The impoverished kingdom is also nervously watching the spread in China of a new H7N9 strain that had not previously been transmitted from birds to humans, but has now killed seven people in China since February.

“We’re monitoring it. We’re constantly on alert,” Sok Touch, head of the Cambodian Health Ministry’s Disease Surveillance Bureau, said of the new type.

So far the kingdom has not recorded any human cases of H7N9 and is focused on fighting the more common H5N1 virus, which has killed more than 370 people globally since 2003, according to the World Health Organization (WHO).

The WHO says H5N1 carries a mortality rate among humans of around 60 percent.