Coronavirus updates: New cases on the rise in 49 states, territories

A four-week partial shutdown began in Germany on Monday, with bars, cinemas, restaurants, theaters and other leisure facilities shuttered until the end of the month.

Unlike the lockdown imposed in the spring amid the first wave of the coronavirus pandemic, schools, nonessential shops and hair salons will remain open.

German Chancellor Angela Merkel and regional authorities will review the situation after two weeks.

The new restrictions come after the European country reported on Saturday its highest number of COVID-19 infections within a 24-hour period -- 19,059 -- since the start of the pandemic. The cumulative total now stands at 545,027 cases with 10,530 deaths, according to the latest data from the Robert Koch Institute, Germany's disease control agency.

Italian Prime Minister Giuseppe Conte announced new nationwide restrictions to tackle the coronavirus pandemic, including an evening curfew and limitations on movement between regions.

Conte outlined the planned measures to lawmakers on Monday, ahead of a new decree expected to be announced soon. He said the decree would include restrictions on movement in the late evening and for regions where the COVID-19 infection rate is highest. Arcades, betting shops, galleries and museums will all be closed, joining cinemas, gyms, pools and theaters which were shuttered under the last set of restrictions.

The new decree will also include the closure of shopping malls on weekends, except for any food stores, pharmacies and newsstands located inside. Meanwhile, high schools and middle schools will be asked to transition to full-time remote learning, according to Conte.

Italy, once the epicenter of the pandemic, is battling a rising number of COVID-19 infections as a second wave hits Europe. The country's civil protection agency confirmed 29,907 new cases on Sunday, including 208 deaths, bringing its cumulative total to 709,335 cases with 38,826 deaths.

ABC News' Phoebe Nathanson contributed to this report.

Dr. Scott Atlas, an adviser on the White House coronavirus task force, has apologized after appearing on a Russian state-funded television network to criticize lockdown measures aimed at curbing the spread of COVID-19.

Atlas addressed the matter via Twitter on Sunday, saying he was "unaware" that RT was a registered foreign agent.

"I regret doing the interview and apologize for allowing myself to be taken advantage of," Atlas tweeted. "I especially apologize to the national security community who is working hard to defend us."

Atlas, a neuroradiologist who was handpicked by President Donald Trump to join the coronavirus task force in August, told RT during a lengthy interview on Saturday that he considered the pandemic to be largely under control and that lockdowns are actually "killing people."

RT, formerly called Russia Today, is registered under the Foreign Agents Registration Act, a U.S. law that applies to people or companies disseminating information in the United States on behalf of foreign governments, political parties and other "foreign principals."

U.S. intelligence agencies have alleged that RT, which broadcasts around the world in English, served as a propaganda outlet for the Kremlin as part of efforts to influence the 2016 U.S. presidential election. Russia denies interfering.

Prince William, Duke of Cambridge, tested positive for COVID-19 in April, royal sources told ABC News.

Wiliam's diagnosis came around the same time his father, Charles, Prince of Wales, also tested positive for the disease. Charles is the heir apparent to the British throne while his eldest son, William, is second in line.

The Court Circular, the official record of past royal engagements, shows that William had a joint engagement with his wife, the Duchess of Cambridge, on April 8 via Zoom. He did a solo virtual engagement -- without Kate -- the following day. His next joint engagement wasn't until May 7.

ABC News' Zoe Magee contributed to this report.