Concerns over the bird flu spreading escalated Friday as avian influenza was detected in Seoul for the first time.

A highly pathogenic H5N8 strain of avian influenza was confirmed from the feces of migratory birds at Jungnangcheon Stream in the western part of the capital, officials said.

The stream is a habitat for more than 4,200 wild birds including mallard ducks. About 600 birds also reside in a national park located near the stream, raising concerns that the virus may further spread.

The Seoul Metropolitan Government immediately blocked public access to the stream and strengthened quarantine measures.

The municipality also vowed to enhance the preventive measures at other streams and Hangang River as part of containment efforts, the city said.

All bird exhibitions at public zoos are closed temporarily, the city government said, and disinfection measures and monitoring systems will be tightened.

But Seoul shrugged off the possibility of the virus affecting humans.

“There have been no cases of avian-to-human transmission. Therefore, there is no need to be worried,” a Seoul city government official said. “But we would like all citizens to refrain from visiting the streams or the Hangang River where the disinfection measures are underway.”

As of Sunday, more than 1.8 million birds, mostly ducks and chickens, have been culled since the disease broke out in December, the Agriculture said. Of the 19 cases confirmed across the country, nine were detected in feces, it added.

The government has tightened its preventive measures since late last year. It enforced a 36-hour halt in the movement of all poultry and farmers last month to stem the spread of the virus.

By Lee Hyun-jeong (rene@heraldcorp.com)