Authorities in South Africa have implemented a cull of some 30,000 ostriches after avian influenza broke out in the Eastern Cape.

Roadblocks have been established in a 20-mile radius around Middleton in the Somerset East area, to prevent exposed birds being transported around the country.

The bird flu outbreak has killed 1,500 ostriches on two large ranches in the Eastern Cape, the Guardian reported.

Officials have ordered the extermination of all potentially exposed birds to prevent the virus from spreading and harming the ostrich industry, which is worth some £108m (US$198.8m) a year.

Hong Kong and Singapore announced bans on all South African poultry products, in a move pre-empted by the South African agricultural department. “The Department of Agriculture has voluntarily stopped exports of poultry and poultry products from South Africa until the outbreak has been dealt with successfully,” the department said in a statement.

South Africa’s ostrich business has been hit by the H5N2 strain, which is different from the H5N1 strain that killed 24 people and millions of chickens when it swept through Asia earlier this year. It is not said to be dangerous for humans.