The most cases of coronavirus confirmed in a single day were reported in the past 24 hours, according to the World Health Organization (WHO).

WHO Director-General Tedros Adhanom Ghebreyesus said at a news conference in Geneva Wednesday that there were 24,363 confirmed cases and 490 dead in China as of Wednesday.

“In the last 24 hours we had the most cases in a single day since the outbreak started,” Tedros said.

Health officials reported coronavirus infections in mainland China rose sharply on Tuesday, with 3,887 additional cases and 65 new deaths reported. WHO said the virus has also been confirmed in 191 cases in 24 countries and one death in the Philippines and another in Hong Kong. Of those, 31 cases are in people with no travel history to China, but all are close contacts of a confirmed case or of someone from Wuhan.

“The relatively small number of cases outside China gives us a window of opportunity to prevent this outbreak from becoming a broader global crisis,” Tedros said. “Our greatest concern is about the potential for spread in countries with weaker health systems, and who lack the capacity to detect or diagnose.”

Tedros said Wednesday WHO has tapped $9 million of funding from its contingency fund for emergencies. The organization has also sent medical supplies and diagnostic tests around the globe.

WHO is also launching a “strategy preparedness and response plan,” and is requesting $675 million to “prevent, detect and diagnose onward transmission,” he said.

Tedros urged people not to panic, saying, “We understand that people are worried and concerned — and rightly so. But this is not a time for fear — it’s a time for rational, evidence-based action and investment, while we still have a window of opportunity to bring this outbreak under control.”