Four cases of Omicron subvariant BF.7 were detected in West Bengal, a health official said on Wednesday.
Genome sequencing of the four people, who have recently returned from the US, confirmed that they were infected with the new variant of the coronavirus, he said.
The condition of the four patients is stable, he said.
Of the four people, three are of the same family and are native of Nadia district, while one person hails from Bihar but currently resides in Kolkata, the official told PTI.
The state health department has found that a total of 33 people have come in contact with these four infected people.
"All the 33 people are healthy and we are monitoring their condition as well," he said.
Since last month, the samples of all people arriving at Kolkata airport from abroad who tested positive for COVID-19 were collected for genome sequencing.
Last week, two persons, including a foreign national, tested positive for COVID-19 at Kolkata airport, and their genome sequencing later confirmed they were infected with the BF.7 subvariant of Omicron.
