A fresh outbreak of bird flu in poultry was detected in the northeastern Indian state of Assam on Wednesday and authorities prepared to start culling thousands of chickens, a senior official said, Reuters reported. "Yes, bird flu has spread to new areas, we are getting ready to start culling in those areas shortly," Ashim Kumar Kakoty, a top veterinary official in Assam, told Reuters. More than 40,000 chickens and ducks have been be slaughtered over the weekend in around 20 villages, after one of them, just 35 km (21 miles) west of Guwahati -- the biggest city in the region -- was hit by bird flu. Authorities were worried about a new outbreak after some poultry deaths were reported in Palasbari, also close to Guwahati. "The newly affected areas cover about 20 villages," Kakoty said. Sale and movement of poultry in and around Guwahati has been prohibited and precautionary measures stepped up in other parts of the state. Health workers have moved to affected areas to check people for any flu-like symptoms.