Chinese authorities have quarantined New Orleans Mayor Ray Nagin and his wife in a Shanghai hotel after a passenger on their flight exhibited flu-like symptoms.

Nagin's office said the couple and a security guard were quarantined Sunday as a precaution and were exhibiting no swine flu symptoms.

Nagin's spokeswoman Ceeon Quiett said the three are "being treated with utmost courtesy by Chinese officials," The Times-Picayune newspaper reported Monday.

Nagin "is feeling well and continues to be in communication with his staff," according to Quiett. She did not know how long they would be quarantined.

Nagin left Friday for an economic development trip. He was to travel next to Australia, where he'd planned to speak on climate change and sustainable building.

China has been enforcing quarantines and temperature checks at airports throughout the country to prevent the virus from spreading.