Four of South Africa's neighbours have banned poultry imports from the rainbow nation following a serious outbreak of a highly contagious strain of avian influenza.

Namibia on Tuesday became the latest country to ban South African chickens -- live and uncooked -- following last week's outbreak of the H5N8 strain of bird flu at two South African poultry farms.

Windhoek followed Botswana, Zimbabwe, and Mozambique, along with Zambia, which had already halted the imports of certain poultry products from South Africa.

Namibia's chief veterinary officer Adrianatus Maseke confirmed in a statement "the suspension of import and 'in-transit' movement of live poultry, birds, poultry products, ostriches and ostrich products from South Africa".

Authorities also suspended imports from Belgium which reported a bird flu outbreak in February.

Zimbabwean government veterinarian Joseph Nyika said that Harare's ban on poultry would be lifted when South Africa confirmed that the situation had been contained -- even though the southern Africa outbreak is thought to have started in Zimbabwean birds earlier this month.

In a bid to contain the outbreak, South Africa is culling thousands of birds and has introduced a nationwide ban on the sale of live chickens.

The H5N8 strain can spread quickly through affected farms, forcing farmers to cull thousands of birds.

South African poultry experts said the strain arrived in the region with birds migrating from Europe.

Since October, the strain has been detected in 15 European countries including Britain, France and Germany.