Two children have been hospitalized in Indonesia with suspected cases of bird flu and a zoo in Jakarta has been closed after tests showed some exotic birds had the virus, the health minister said Monday.

The deadly H5N1 strain of the virus has killed four Indonesians, including one woman who died in Jakarta a week ago. The virus has killed 64 people in four Asian countries since late 2003 and has also spread to Russia and Europe.

"Until now, three children are being treated in a hospital . . . two are suspected of having the symptoms of bird flu based on the lab tests. The other one is still under observation," Health Minister Siti Fadilah Supari told the local el-Shinta radio.

Indonesia sends blood tests from all suspected bird flu cases to Hong Kong for confirmation.

Agriculture Minister Anton Apriantono said 19 birds in the zoo had the virus, the Jakarta Post newspaper reported. Over the weekend, tens of thousands of people visited the zoo.

The government would kill those birds at the zoo which had tested positive for the virus, Supari said.

Health officials last week said that bird flu had killed a 37-year-old woman who lived near a chicken farm in south Jakarta, and that another person who had close contact with her was suspected of having the virus.

The World Health Organization said last week that bird flu was moving toward becoming transmissible by humans. Most of those killed in Asia since 2003 caught the virus from infected birds. Health experts have said the greatest worry is that H5N1 could mutate and become transmissible between people.