The results come three days after samples taken from crows and ducks in the national capital tested positive for avian influenza. This had led to the Delhi government on Monday banning the sale of processed and packaged chicken brought from outside the city.

The government had also shut down the poultry market for 10 days as a precautionary measure.

''Test results of 104 samples arrived on Wednesday evening. Of these, 100 samples were collected from 35 poultry birds in the Ghazipur market. All samples have tested negative for bird flu,'' senior Animal Husbandry Unit officer Rakesh Singh said.

''It means there is no spread of avian influenza in poultry birds in Delhi,'' he said.

The remaining four samples of Heron birds were taken from the Hastsal Park and bird flu is suspected in these four cases, Singh said, adding that these samples have been sent from a Jalandhar-based lab to Bhopal for confirmation.

Civic authorities had on Wednesday imposed a temporary ban on sale and storage of poultry or processed chicken meat in view of the bird flu situation here.

The three municipal corporations of the city had warned establishments like restaurants and shops of strict action, including cancellation of their licence, if they fail to comply with the orders.

Officials had earlier said that 10 samples from three areas – Mayur Vihar Phase-3, Sanjay Lake and Dwarka Sector-9 – tested positive for avian influenza.

A drive to cull ducks was conducted on Monday at the Sanjay Lake, where several of these were found dead.