NEW YORK: The dollar rose for the first time in six days on Thursday, as investors grew cautious about the persistent rise in coronavirus infections that forced localized shutdowns around the world, with broad optimism about upcoming COVID-19 vaccines fading a bit.

The US death toll from COVID-19 passed 250,000 on Wednesday as New York City's public school system, the country's largest, halted in-person instruction, citing a jump in infection rates.

In mid-morning trading, an index which tracks the dollar against a basket of currencies was up 0.1% at 92.576.

"The dollar's strength is a spillover from the New York public school closures and the S&P 500 falling 1% to the close, which created a risk-off theme," said Erik Bregar, head of FX strategy, at Exchange Bank of Canada in Toronto.

The dollar was also caught between two opposing forces, with a safety bid supporting it while renewed speculation over monetary easing to boost the economy held it back somewhat.

The euro slipped 0.2% against the dollar to $1.1830.

With fiscal stimulus plans falling by the wayside as President Donald Trump's refusal to concede electoral defeat consumes lawmakers' attention, speculation is growing that the Federal Reserve may further loosen monetary policy in December.

Two Fed officials on Wednesday held out the option of doing more, and Treasuries have rallied in anticipation of a possible expansion of Fed bond buying.

Still, the Scandinavian currencies and the Australian dollar -- beneficiaries of the dollar's recent decline -- fell.

The Norwegian crown fell 0.5% against the US dollar, which rose to 9.0350. The dollar also gained against the Swedish crown, up 0.3% at 8.6311, while the Aussie dollar also fell 0.4% to US$0.7273.

"It seems that market participants are confused. They don't know where to place more emphasis, on the positive vaccine headlines or on the acceleration of the infections from the pandemic," said Charalambos Pissouros, senior market analyst at JFD Group.

Pissouros said he was sticking to his guns, however, "that any declines in risk-linked assets are likely to stay limited."

The dollar rose 0.2% against the yen to 103.965 yen. The yen has gained 1.6% in the week since Pfizer announced promising trial results on its COVID-19 vaccine.

The greenback showed little reaction though after data showed US weekly jobless claims increased to a seasonally-adjusted 742,000 for the week ended Nov. 14. Economists polled by Reuters had forecast 707,000 applications for the latest week.

Elsewhere, sterling dipped 0.3% to $1.3226 against the dollar after The Times newspaper reported that European leaders will urge the European Commission to publish no-deal Brexit plans as the year-end deadline approaches.

Bitcoin rose 1.9% on Thursday to $18,126 not far from the all-time high of nearly $20,000 reached three years ago.