The government imposed "extraordinary" measures Tuesday to contain a bird flu (search) outbreak that has killed four people in Indonesia, including the forced hospitalization of people with symptoms of the disease.

In addition to the fatalities, seven patients suspected of having the H5N1 strain of bird flu (search) — two of them zoo employees — have been admitted to Jakarta's infectious diseases hospital, officials said.

Blood samples from the patients have been sent to Hong Kong for testing.

Health Minister Siti Fadila Supari assured the public there was no reason to panic, saying the government was taking the outbreak seriously and had assigned 44 state-owned hospitals to treat avian influenza patients and make sure all receive free medication.

Those with symptoms of the disease — including high fever, coughing and breathing difficulties — could be forcibly admitted to hospitals, Supari said.

She said a 21-day state of high alert against the disease, issued Tuesday by the government, could be extended if necessary.

Meanwhile, zoos across the sprawling archipelago (search) were taking measures to protect their animals after 19 eagles, peacocks and other birds tested positive for the virus at the popular Ragunan Zoo in the capital, Jakarta, forcing it to close for three weeks.

Two of its employees — a 28-year-old guide and a 39-year-old vendor — were hospitalized Tuesday with bird flu symptoms, said I Nyoman Kandun, director general of Communicable Disease Control.

Other Indonesian zoos were testing birds for the virus. Some sprayed disinfectant in bird cages and stopped accepting new animals.

"With such measures, we believe the park is safe," said Asep Firmansyah, a spokesman for Taman Safari Indonesia, just outside Jakarta. "However, we will welcome health officials testing the birds at this park."

The virus has swept through poultry populations in large swaths of Asia since 2003, killing 63 people and resulting in the deaths of tens of millions of birds.

Most human cases have been linked to contact with sick birds. But the World Health Organization (search) has warned that the virus could mutate into a form that can easily spread among humans, possibly triggering a global pandemic that could kill millions.

Supari said the government would stockpile 10,000 tablets of Tamiflu (search) — the only treatment so far proven effective against bird flu in humans — enough for about 1,000 victims.

The Agriculture Ministry also said it would push to amend the current farm law to allow for sanctions against chicken farmers who refuse to cull birds sickened by the virus.