Disease experts have been rushed to the district in a bid to reassure villagers that they are not in danger, said Dr Thawat Suntaracharn, the director-general of disease control for Thailand´s Public Health Ministry.

Hundreds of pigeon carcasses were found at Sri Saliam primary school and nearby Thung Saliam kindergarten in Sukhothai´s Thung Saliam district on Nov 5.

But panic broke out only after the cause of death was confirmed by a provincial science centre on Wednesday.

The affected schools, with a total of 500 students, were immediately closed, and both teachers and students told to leave the area, reported the Bangkok Post.

It is the first time bird flu has been recorded in the district. However, an outbreak swept through one nearby district earlier this year and a woman in another died of bird flu last month.

Even so, Dr Thawat said the school closure was an ´over-reaction´ that sparked unnecessary concern.

The students will be closely watched for bird flu symptoms, which has a two-week incubation period.

So far, none has shown symptoms.

The province´s public health chief, Dr Somchai Rojanarattanangkul, said health volunteers were already travelling around the district teaching the locals how to contain the outbreak and monitor for symptoms.

Villagers should not touch the dead birds with bare hands or go into the affected area without a mask and other protection, he said.

MASS MIGRATION

The director of Thailand´s anti-bird flu operation centre, Mr Charal Trinvuthipong, said agricultural officials were investigating how widespread the outbreak was.

He believed the birds had contracted the virus elsewhere before flying as a flock into the area.

Meanwhile, an outbreak of bird flu that killed 83 tigers at Chon Buri last month has been declared under control.

More than 5,000 Thai and foreign tourists flocked to Si Racha Tiger Zoo when it unofficially reopened yesterday after a month-long quarantine.