New Delhi, April 21 -- US stock indices opened lower on Monday after President Donald Trump's renewed attacks against Federal Reserve Chair Jerome Powell sparked concerns about the central bank's independence.

At the opening bell, the Dow Jones Industrial Average fell 236.2 points, or 0.60%, to 38,906.04. The S&P 500 fell 49.8 points, or 0.94%, to 5,232.94​, while the Nasdaq Composite dropped 233.7 points, or 1.43%, to 16,052.764.

National Economic Council Director Kevin Hassett said on Friday that Trump is studying whether he's able to fire Powell. The comments raise new questions about whether the Fed can maintain its longstanding independence with the president increasingly venting disatisfaction in harsh terms that the central...