Shares of drugmaker Lupin declined nearly 19% on Tuesday after the company said its Goa and Indore units had received warning letters from the United States drug regulator for violating goods manufacturing practices.

The pharmaceutical firm received the letter from the US Food and Drug Administration on Monday.

“We are deeply disappointed to have received this outcome,” Lupin said in a filing to the stock exchanges. “While there will be no disruption to existing product supplies from either of these locations, there will likely be a delay in new product approvals from these two facilities.”

Lupin was the top loser on both Sensex and Nifty on Tuesday, ending the day 16.9% lower from Monday’s close.

“We plan to address the concerns raised by the US FDA expeditiously and will work with the US FDA to resolve these issues at the earliest,” the company said.