By Bappa Majumdar

NEW DELHI, March 9 (Reuters) - A fresh outbreak of bird flu in poultry has been reported from an eastern Indian state, officials said on Sunday, a month after authorities there said they had contained the virus.

The outbreak, the fifth in India since 2006, has been reported from two villages of West Bengal state's Murshidabad district, officials said.

"We are worried that bird flu has returned to West Bengal because the outbreak seemed to be under control," Anisur Rahaman, West Bengal's animal resources minister told Reuters on Sunday.

In January, the H5N1 virus affected 13 of the state's 19 districts, including Murshidabad. The strain of the latest virus was still being tested, but Rahaman said preliminary checks have indicated the H5N1 strain.

More than 3.4 million birds were culled during the last outbreak, which the World Health Organization (WHO) described as the worst-ever in India.

India has not reported any human bird flu cases, but the earlier outbreaks had badly hit poultry businesses in West Bengal and had a limited effect on poultry sales elsewhere in the country.

The virus could have now resurfaced from infected backyard poultry saved from culling by villagers, Rahaman said.

"We are trying to find out the reasons, but it seems that villagers had hidden ducks and chickens during the previous culling operation," Rahaman said by phone from the state capital, Kolkata.

More than 900 chickens and ducks had died over the past two weeks in the two villages and officials said they would cull a few thousand poultry to contain the latest outbreak in the area, about 300 km (185 miles) north of Kolkata.

Smuggled poultry from bird flu-hit Bangladesh, which borders West Bengal, could have also triggered the latest outbreak, Rahaman said.

Previous containment efforts in West Bengal had been hampered because of the unwillingness of villagers to hand over poultry for culling. Large-scale ignorance about the disease and how it spreads was also a problem.

Many villagers had even dumped dead birds into drinking water wells and ponds.

On Sunday, authorities in Murshidabad used loudspeakers to warn villagers to stay away from backyard poultry and cooperate with culling teams.

"We will begin culling operations later today. People should not panic," Subir Bhadra, a senior district official said.

Officials were also checking people for flu-like symptoms.

Experts fear the H5N1 strain could mutate into a form easily transmitted from person to person, leading to a pandemic that could kill millions worldwide.

The WHO said recently the virus was firmly entrenched in Asia and a pandemic among humans was possible.

About 60 percent of India's 1 billion plus people live in rural areas close to livestock, just as in many other parts of Asia, raising the risks of the bird flu virus infecting people.

Last month, the Food and Agriculture Organisation praised West Bengal's containment efforts but warned that intensive surveillance should continue as the possibility of new outbreaks remained high. (Editing by Krittivas Mukherjee and David Fogarty)

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