The death toll from the new coronavirus in China surged and the U.S. and Europe confirmed new cases as travelers from the outbreak’s center in Wuhan have returned home and developed symptoms.

Chinese regional authorities said Saturday that an additional 15 people died in Hubei province, where Wuhan in located, bringing the total death toll there to 39. They said 180 new cases were reported as well.

The dramatic rise in the death count in China could be a signal that the virus isn’t yet under control despite aggressive steps by authorities there to limit travel for millions of people who live in the cities at the center of the outbreak. Scientists around the globe have been working to understand the virus better, how contagious it is and where it comes from.

While movement from the heart of the cases in Wuhan and nearby areas has been limited, thousands of people left the region for other points before the bans took effect. In the U.S., two cases have been confirmed in people who returned from China. And in France, Europe’s first cases were identified on Friday.

The virus, first detected in the city of Wuhan last month, has sparked fears that the disease that could rival SARS, the pandemic that claimed almost 800 lives 17 years ago.

While global experts have mostly praised efforts to contain the virus, Chinese citizens are increasingly critical and anxious as the travel restrictions grow to encompass a population bigger than Australia. The restrictions come during the Lunar New Year, the country’s biggest celebration during which billions of trips are typically taken to vacation and visit family.

Beyond the restricted areas near Wuhan, major closures took place across the country amid the health fears. Public events to mark the new year were canceled, Shanghai Disneyland announced that it was closing indefinitely, and cinema chains canceled movie screenings. The halt to activity comes during what is usually a peak period for spending, putting China’s economic stabilization at risk.

U.S. President Donald Trump, who is negotiating a trade agreement with China, praised its efforts to control the outbreak and thanked his counterpart, Xi Jinping.

“China has been working very hard to contain the Coronavirus,” Trump said in a tweet Friday.

Late Friday, France’s Health Ministry confirmed three cases of the coronavirus, the first reported infections in Europe. The first case is in Bordeaux, and the other two are in Paris -- all three had been on a trip to China.

“We will do everything possible to keep this epidemic under control while knowing it’s possible, even probable, that there will be other cases, particularly in Europe,” Health Minister Agnès Buzyn said at a press briefing.

In the U.S., two cases have been reported and health authorities are monitoring more than 60 people for potential infection. U.S. lawmakers said health authorities are expected to confirm a third case of coronavirus, following a closed-door briefing between lawmakers in Washington and federal health officials.

“We are expecting more cases in the U.S. and we are likely going to see some cases among close contacts of travelers and human-to-human transmission,” said Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases.

Three people in New York state are being investigated for possible infection, according to Governor Andrew Cuomo’s office. A fourth person has been investigated and tested negative.

The virus is believed to have emerged last month in a seafood and wildlife market in Wuhan, spreading from infected animals to humans. It has an incubation period of about two weeks before infected people start to show symptoms, which resemble a cold or flu, the CDC said.

The CDC said it’s working to get tests for the virus out to states so they can more quickly identify cases. Currently, samples have to be sent to the CDC for analysis.

“This situation is rapidly evolving. Information is coming in hour by hour, day by day,” Messonnier said.