Saudi authorities have culled about 50,000 birds following the detection of the lethal H5N1 strain of bird flu at a poulty farm, a report said.

The Agriculture Ministry said tests were carried out after 1,500 birds died in a farm of the Al-Kharj region, 150 km south of Riyadh.

All the birds on the farm were culled and the area disinfected, the ministry said in a statement carried  by the official SPA news agency.

It said no human case has been found and an investigation was taking place to determine the origin of the illness.