Coronavirus infections in mainland China again rose sharply, with nearly 3,700 additional cases and 73 new deaths reported on Wednesday alone, authorities said Thursday morning. China’s total confirmed cases now top 28,000, more than 3,800 of them critical.

The increase continues a trend of growing daily spikes in confirmed cases. China has reported more than 560 coronavirus deaths, and another person died in the Philippines.

Here are the latest developments:

● U.S. officials have quarantined nine people since stringent travel restrictions went into effect Sunday, a top U.S. health official said.

● Hundreds of people evacuated from Wuhan on U.S.-chartered flights will be held in quarantine on military bases in California. One passenger described the scene as “so disorganized” after what several described as a frustrating experience in Wuhan.

● Wisconsin confirmed its first coronavirus patient, raising the number of known U.S. cases to 12.

● Hong Kong will enforce a mandatory 14-day quarantine for everyone arriving from mainland China, including foreigners and Hong Kong residents. Hong Kong leader Carrie Lam is facing a medical workers’ strike and worries that the virus will spread in the community. Twenty-one cases have been confirmed.

● A plane traveling from Seoul to Las Vegas was briefly diverted to Los Angeles when officials learned that some passengers recently had traveled through China.

● A Chinese disease expert says containing the virus and reducing the number of infections could take up to six weeks.