China said on Friday local time that the total number of coronavirus cases in mainland China rose to 830 and the death toll has risen to 25. It comes as the fast-spreading infection prompted local authorities to quarantine several major cities and cancel Lunar New Year's events in Beijing and elsewhere.

The virus — which was first diagnosed less than a month ago — has also infected at least 15 people around the world, mostly in Asia. The Saudi Center for Disease Prevention and Control on Friday tweeted a statement refuting earlier reports that there was a case in Saudi Arabia.

Medical teams have been dispatched across China, and hospitals are asking for donations of essential items, including face masks, eye protectors, protective uniforms and sanitizer.

Local authorities in China have quarantined Wuhan and Huanggang, which have a combined population of 17 million. Including Wuhan where the virus was first identified, travel bans were in effect Thursday for at least eight cities.

China is offering to refund domestic flights and train tickets nationwide. An estimated 246,000 travelers arrived in Wuhan either via plane or train on Thursday before all transportation in and out of the city was shut down. The number of people leaving the city is currently unknown.

The U.S. State Department on Thursday reiterated its level 2 travel advisory, indicating travels should "exercise increased caution." The department earlier on Thursday errantly raised its travel advisory and urged citizens to "reconsider travel," but reverted that change. The agency, in a statement, said its website "briefly displayed an inaccurate version of the Advisory due to a technical error – we apologize for any confusion. Again, the Advisory level has not changed."

In a statement, American Airlines said the airline has been working with its medical director to make crew members aware of the latest updates on the virus. "Beginning on Thursday, American increased provisions of hand sanitizer wipes for flight attendants to use on all American Airlines departures to China," the airline said. "The safety of our customers and team members is our top priority."