ST. PETERSBURG - The deadly bird flu virus originated naturally, and is not a biological weapon, a senior Russian scientist said Thursday. Oleg Kiselyov, the head of the Russian Influenza Research Institute, said: "We have not advanced enough to create such a genetic machine."

He said if the virus had been created artificially in order to be used as a biological weapon, scientists would have identified this.

"We know the genealogy of the virus," Kiselyov said. "If the virus was artificial, we would have realized."

He said international agreements on biological security needed to be signed to effectively fight the spread of avian flu.

He added that the Russian and Chinese academies of medical sciences had already signed a draft agreement on the issue, and that similar agreements were to be signed with neighboring countries.

"Work in this area is not keeping up to pace," he said. "We need to have swift information on what is happening in neighboring countries. Monitoring must be global."

Russia registered its first bird flu cases in Siberian birds last summer, and saw the virus spread west of the Ural Mountains to the European part of the country in October. However, no cases of human infection have been reported.