The North's Korean Central News Agency quoted quarantine official Ri Kyong Gun as saying all poultry in provinces near the border with the South have received emergency vaccinations, citing a bird flu outbreak in southern South Korea.

South Korea has slaughtered about 6.5 million chickens, ducks and other poultry since early last month when bird flu broke out there for the first time in more than a year.

Mr Ri was quoted as saying the North has also set up 1,600 observation posts along the east and west coasts to monitor the movement of migratory birds - which he said are a key way the virus spreads.

The North has intensified its quarantine efforts on poultry farms and ordered farmers to keep their poultry in pens to stop them from coming into contact with migratory birds, it said.

The North banned South Korean poultry and eggs from a joint South-North industrial zone late last month, according to the Kaesong Industrial District Management Committee.

South Korea had been sending 85,000 tonnes of chicken and 127,000 eggs to the complex in the North Korean border city of Kaesong every month for food for workers there, according to the South Korean Unification Ministry.

Bird flu hit North Korea in 2005, leading to the killing of about 210,000 birds, but no new cases have been reported since then. -- AP