A trader wearing a face covering works on the trading floor of the New York Stock Exchange in New York, the United States, on May 26, 2020. (Colin Ziemer/NYSE/Handout via Xinhua)

The major averages of U.S. stocks posted their worst day since mid-March, with concerns over the increase of COVID-19 cases in some U.S. states after reopening.

NEW YORK, June 11 -- U.S. stocks ended sharply lower on Thursday with the Dow plunging more than 1,800 points amid a broad market sell-off.

The 30-stock index shed 1,861.82 points, or 6.9 percent, to 25,128.17. The S&P 500 sank 188.04 points, or 5.89 percent, to 3,002.1. The Nasdaq decreased 527.62 points, or 5.27 percent, to 9,492.73. The major averages posted their worst day since mid-March.

All the 11 primary S&P 500 sectors tumbled, with energy and financials down 9.45 percent and 8.18 percent, respectively, leading the losses.

The moves came as coronavirus cases increased in some U.S. states reopening after lockdowns.

More than 2 million confirmed COVID-19 cases have been reported in the United States, with over 113,000 deaths as of Thursday afternoon, according to the Center for Systems Science and Engineering at Johns Hopkins University.

Investors also digested the U.S. Federal Reserve's latest monetary policy and its grim forecast for the economy.

The Fed on Wednesday kept its benchmark interest rate unchanged at the record-low level of near zero amid mounting fallout from the COVID-19-induced recession, and indicated interest rates would remain at the current level through at least 2022.

On the data front, U.S. initial jobless claims registered 1.542 million in the week ending June 6, as the pandemic continues to weigh on the labor market, the Department of Labor reported on Thursday. The previous week's level was revised higher to 1.897 million.