Preliminary tests on a common kestrel found dead in Hong Kong have indicated it was infected with the milder H5 strain of bird flu.

The bird was found in Pak Tin estate on Tuesday, a spokesman for the Agriculture, Fisheries and Conservation Department said in a statement Saturday, adding that further tests were now being conducted.

The H5N1 strain of the virus is potentially deadly to humans, while H5 is less virulent.

Hong Kong was the scene of the world´s first reported major bird flu outbreak among humans in 1997, when six people died of a then unknown mutation of the avian flu virus. Millions of poultry were culled.

At least seven birds have been found dead with H5N1 in Hong Kong so far this year.