CARLSBAD -- Three more students and a teacher from a Carlsbad private school are set to return home Tuesday after being quarantined during a class trip to China because some in their group developed swine flu.

On Saturday, 29 students and five teachers from Pacific Ridge School arrived home to Carlsbad. They were among 42 people from the school who were quarantined for several days in Yichang, a city of about 4 million people. Six students and one teacher were hospitalized there after they came down with the virus.

On Monday, two students and a teacher remained hospitalized. The school has not released their names, but has said all who contracted the disease are recovering and doing well.

The ninth-grade students and teachers were on a 13-day educational tour in China when some developed mild flu symptoms, including upset stomachs and sniffles, aboard a river cruise to the Three Gorges Dam, officials said. They saw a doctor on the boat and were later admitted to a nearby hospital.

Pacific Ridge is a nonprofit private secondary school that opened in 2007 in Carlsbad's Bressi Ranch area. It has more than 200 students in grades seven through 10.