"The pathogenicity of this virus for humans has not been confirmed," Gennady Onishchenko said.
Bird flu cases have been detected in a private farmstead in the Domodedovo District's town of Pavlovsky, where households have a total of about 700 birds, he said.
Onishchenko said it was highly unlikely that the virus will spread to commercial poultry producers.
"Poultry farms in the Domodedovo District are modern and self-contained operations," he said.
Acting Governor Alexei Panteleyev said bird flu cases have also been detected in the Odintsovo district, west of Moscow.
"The [sick] birds - fewer than a hundred in all - have been culled," he said.
He said that people who may have been in contact with the dead birds are now in hospital, undergoing medical tests.
Russia's most recent bird flu outbreak occurred in mid-January, in the southern region of Krasnodar, but it was contained by February.
