Genome sequencing and analysis of samples from Maharashtra state found mutations in the virus that do not match previously catalogued “variants of concern” (VOC), the ministry said in a statement on Wednesday.

Maharashtra is one of India’s worst-affected states but the ministry said it was not clear if the new variant was causing a surge there or in other states.

“Though VOCs and a new double mutant variant have been found in India, these have not been detected in numbers sufficient to either establish a direct relationship or explain the rapid increase in cases in some states,” the ministry said in a statement but did not elaborate.

India has already reported several cases of a variant first detected in Britain, as well as ones first found in South Africa and Brazil.