NEW YORK: Wall Street stocks tumbled at the open Thursday on global growth worries in light of dropping bond yields and rising instances of the Delta variant of the coronavirus.

The yield on the 10-year US Treasury bond fell below 1.3 percent, extending a trend from recent weeks as inflation fears ebb.

Meanwhile, Japan's government announced a new virus state of emergency that will run through the Olympics, meaning spectators will be banned from the games' venues.

The move comes amid fears the Delta variant will prolong the economic downturn in many countries.

US stocks climb ahead of Fed minutes

About 15 minutes into trading, the Dow Jones Industrial Average was down 1.4 percent at 34,184.56.

The broad-based S&P 500 fell 1.5 percent to 4,292.60, while the tech-rich Nasdaq Composite Index shed 1.7 percent to 14,420.68.

Both the S&P 500 and Nasdaq had ended at records on Wednesday.

US jobless claims edged higher to 373,000, seasonally adjusted, in the week ending July 3. That was 2,000 more than the previous week's report, which was the lowest reading since the Covid-19 crisis began.