South Africa will cull 2,200 ostriches after identifying three more farms in the country’s Eastern Cape province where bird flu might have spread, officials said on Wednesday.

“The decision has been taken to cull on three farms (in the Eastern Cape),” agriculture ministry spokesman Segoati Mahlangu told AMN Health.

He said starting on Tuesday around 500 ostriches had been culled and the rest should be killed by the end of the week.

The farms are around 120 kilometers (75 miles) from the area where the initial outbreak had been detected, but Mahlangu said this did not mean the disease was spreading.

“We are monitoring the situation on all farms…on a daily basis,” he said.

Mahlangu said the three farms had been under quarantine since October and that authorities suspected the disease might have spread from contact with people or animals where the original outbreak was spotted in August.

South African officials have identified the flu as the H5N2 strain of the disease - prompting a temporary import ban from the EU on South African ostrich meat.

Officials say the H5N2 is lethal for birds but different to the H5N1 strain that has killed 20 people in Vietnam and 12 in Thailand this year.

Some 15,000 ostriches have been slaughtered so far.

South Africa exports only small quantities of ostrich meat to the EU and is not authorized to ship poultry or wild and farmed feathered game and their meats into the 25-nation bloc.

Fully-grown ostriches are the largest birds in the world. They are mostly used for their meat and feathers, as well as to make oil and leather.