Bhubaneswar, Dec 16 (IANS) At least six lakh migratory birds from places as far as Siberia and Ukraine have arrived at Orissa's Chilika lake, officials said Wednesday.

'About three lakh of them have been sighted in Nalabana - an island inside the lake,' assistant forest conservator (wildlife) B.K.Mohapatra told IANS.

Spread across the districts of Puri, Khordha and Ganjam along the east coast, and about 100 km from state capital Bhubaneswar, Chilika is known for its immaculate scenic beauty and rich bio-diversity.

Every year about a million migratory birds from places like Siberia, Iran, Iraq, Afghanistan and the Himalayas come to the lake in October and return in March.

The most attractive birds sighted in the lake are flamingos, grey and purple herons, egrets, spoonbills, storks and white ibis.

'We have set up at least 21 camps around the lake and deployed nearly a hundred officials and villagers to ensure that none of the birds are killed by poachers,' Mohapatra said. Five people were arrested recently for killing birds in the lake, he added.

Last year over eight lakh birds belonging to 168 species were counted in the lake. This year the bird census in the lake would be held for two days starting from Jan 11, Mohapatra said.

Chilika was declared one of the six wetlands of international importance for Arctic and Central Asian waterfowl by the Ramsar Convention on Wetlands.