New Delhi - Indian authorities on Wednesday confirmed an outbreak of avian influenza in the north-eastern Sikkim state.

A federal Health Ministry statement said local authorities formally notified all agencies concerned about an outbreak of avian influenza in the Hospital Road area of Ravongla town in South Sikkim district.

A rapid-response team reached the Sikkim capital Gangtok and was assisting state health authorities in containment measures, it said.

Outbreaks of bird flu were reported earlier from northern districts of India's West Bengal state which borders Sikkim and neighbouring Nepal.

Containment efforts are ongoing in West Bengal and north-eastern Assam state to prevent the disease spreading to new areas. At least 480,000 poultry have been culled in those two states, another health department press release said.

Avian influenza mainly affects poultry and wild birds but can infect humans who come in close contact with sick fowl.

India has so far seen four major outbreaks of bird flu but not yet reported any cases of human infections with the H5N1 virus. (dpa)