India is fast-tracking environmental clearances for projects like power plants and coal mines in a bid to boost growth, setting off alarm bells among environmentalists and affected residents who say the decisions are being made too quickly.

In a country where state machinery typically moves slowly, the Environment Ministry under Prime Minister Narendra Modi has slashed the average time taken to grant clearances to 170 days from 600 days, said two government sources with direct knowledge of the matter.

"We're standardizing processes and taking decisions swiftly," said one of the officials, who did not want to be named, citing government policy. "We know the basic issues, and merely taking more time for approvals does not mean much."