With the sudden death of several crows in Delhi's Mayur Vihar Phase III area stirring panic amid a nation-wide bird flu scare, government officials said on Saturday that their samples have been sent to Bhopal to ascertain the cause of death.

"Samples of four crows have been sent to Bhopal's National Institute of High Security Animal Diseases," Director of Delhi's Animal Husbandry Department, Rakesh Singh, told IANS.

"The reports are expected to come by January 12-13 and only then we will be able to ascertain if it is bird blue," he added.

Besides Mayur Vihar, carcasses of crows have also been found in Dwarka as well as Hastsal in west Delhi in the past few days. Further, reports of unusual mortality in ducks have also been received from Sanjay lake in east Delhi.

Samples from Hatsal have been sent to the Northen Regional Disease Laboratory in Jalandhar, while the rest have been sent to Bhopal.

In the wake of bird flu outbreak in several states, the Delhi government has banned import of live birds with immediate effect, besides setting up a 24-hour helpline and closing the Ghazipur poultry market for the next 10 days.

So far, the disease has been confirmed in seven states -- Kerala, Rajasthan, Madhya Pradesh, Himachal Pradesh, Haryana, Gujarat and Uttar Pradesh.

In a communication to the chief secretaries and administrators of the states and UTs, the Secretary of the Department of Animal Husbandry and Dairying has requested the Animal Husbandry departments to ensure effective communication and coordination with health authorities for close vigilance of the disease status and avoid any chances of jumping of the disease into humans.

Besides increasing surveillance around the water bodies, live bird markets, zoos, poultry farms etc., proper disposal of carcass and strengthening of bio-security in poultry farms have to be ensured, the Department of Animal Husbandry and Dairying said.

States have also been requested to be prepared for any eventuality of avian influenza and have been requested to ensure sufficient stock of PPE kits and accessories required for culling operations.

Chief secretaries and administrators have been requested to issue appropriate advisories to increase awareness regarding safety of poultry products that are safe for consumption after boiling and cooking procedures.

Avian influenza viruses have been circulating worldwide for centuries with four known major outbreaks recorded in the last century. India had notified the first outbreak of avian influenza in 2006.

In India, the disease spreads mainly through migratory birds coming into India during winter months, i.e., from September-October to February-March. The secondary spread by human handling, through fomites, cannot be ruled out.

Implementing management practices that incorporate bio security principles, personal hygiene, and cleaning and disinfection protocols, as well as cooking and processing standards, are effective means of controlling the spread of avian influenza.