Upma Chawdhry, joint secretary in Indias Animal Husbandry Department, said that authorities in the remote state of Mizoram had been told to ensure no poultry was smuggled in from Myanmar. Vigil has been hugely stepped up on the Mizoram border, she said. Mizoram has a porous 400-km frontier with Myanmar, seen by some international experts as a potential black hole in the fight against bird flu. Local officials in Mizoram said that veterinarians were monitoring poultry health in the state more closely and rapid response teams were on stand-by to respond to any report of bird flu. India, which shares a 1,600-km (1,000-mile) border with Myanmar, is fighting an outbreak of the H5N1 strain in chickens in Manipur state, which lies north of Mizoram and also borders Myanmar. Authorities said that they had culled around 1,40,000 chickens in and around a small poultry farm near Imphal, Manipurs capital, since announcing the outbreak of the H5N1 virus last week. But there were no reports of any suspected human infections, after 21 people on the poultry farm tested negative for bird flu.