A total of 740 poultry have died from the virus which emerged in the two egg farms located in the central state of Aguascalientes, said a report by the Mexican agriculture ministry to Paris-based OIE.

The virus, reported to be the highly pathogenic avian influenza serotype H7N3, is different from the deadly H5N1 strain, which has devastated duck and chicken flocks and caused hundreds of human deaths after it was first detected in 1997 in Hong Kong.

Outbreaks of H7N3 occurred previously in Mexico, with the latest one in September last year in the northeastern part of the state of Jalisco, which is near Aguascalientes, it said.

"Timely notification from the farmer and surveillance activities allowed immediate depopulation of the two affected production units, reason why both outbreaks identified are closed," the ministry said in the report.

Countries that are members of OIE have the obligation to report outbreaks of certain animal diseases to the Paris-based organisation.

The ministry said it was still doing active and passive surveillance at national level and that epidemiological investigation was ongoing. The source of the outbreaks or origin of the infection was still unknown.

Center>Copyright Reuters, 2013