NEW DELHI (AFP) - India on Wednesday reported an outbreak of bird flu among poultry, the first since it declared itself free of the disease last August.

The government's department of animal husbandry said it had started to cull tens of thousands of birds in the northeastern state of Manipur, where 132 of 144 chickens at a small poultry farm died earlier this month.

The health ministry said it had rushed "rapid response teams" to test 450,000 people for possible symptoms of bird flu within a ten-kilometre (six-mile) radius of the infected zone in Manipur's Imphal state capital district.

Charusheela Sohony, who heads the animal husbandry department, said the infected birds died within a six-day period from July 7.

"Samples taken from the dead as well as the remaining stock are positive" for highly pathogenic H5 avian influenza, Sohony said, adding a "containment process" was underway to prevent the disease spreading.

She told reporters tests were being carried out to ascertain whether the chickens had the virulent H5N1 strain of avian influenza.

"The culling of 150,000 chickens has started in 128 poultry (farms) in a five-kilometre radius of Chingmeirong village where bird flu has been confirmed," she said.

"The disease appears to be very localised and limited presently to one unit in the state," said Sohony.

Health ministry official Vineet Chowdhury said 21 family members directly exposed to the infected chickens in Chingmeirong were being given the anti-viral drug Oseltamivir.

"So far none has showed any symptoms of infection," he said.

"We have sent 40 medical teams to survey 80,000 households in a timeframe of ten days," Chowdhury said.

Manipur borders Myanmar, which has reported two outbreaks of the H5N1 strain among its poultry flocks this year. Indian officials said authorities were investigating whether the infection had come from outside Manipur.

While officials in the northeast said there was no cause for alarm, people in Manipur were starting to worry.

"People have already stopped eating chicken or even eggs," Mani Singh, an Imphal businessman told AFP.

India declared itself free of bird flu last August after a February 2006 outbreak which saw authorities kill tens of thousands of birds.

The World Health Organisation has recorded 319 cases of bird flu in humans, of which 192 have resulted in deaths, according to Wednesday's most recent tally.

Scientists fear the bird flu virus could mutate into a form easily spread among humans, leading to a global pandemic with the potential to kill millions.

These fears have been especially prevalent in India, a country of more than one billion people where many live close to poultry.

Since the 2006 outbreak, India has tested 170,000 samples in ongoing national surveillance of its poultry sector, the government said.