Three Hawai'i students who had been diagnosed with swine flu were released yesterday from quarantine at a Seoul hospital, while seven other members of the study trip remained in hospitals and will likely be released this weekend.

Six of those still in hospitals are students, and one is a chaperone.

Another student who had been quarantined for swine flu was released Thursday.

Meanwhile, a second chaperone is in the hospital with pneumonia.

In all, 11 of the 25 people on the trip were found to have swine flu.

The chaperone in the hospital with pneumonia also tested positive for the H1N1 virus, according to an official with the South Korean consulate in Hawai'i, but officials with the trip couldn't confirm that.

Ruth Limtiaco, a board member and spokeswoman for the Pacific and Asian Affairs Council, which organized the trip for high schoolers, said the study group is set to return to Hawai'i on July 5 but that PAAC officials are looking into whether they can extend the stay in South Korea to make up for time lost while members of the group were in quarantine.

The group consists of four chaperones, 19 high school students and two students who graduated from high school this year and are producing a documentary on the trip. They arrived in Seoul on Monday on a Japan Airlines flight from Honolulu that stopped in Tokyo, and five of the students were quarantined at the Seoul airport after they were found to have elevated temperatures. The five students had swine flu, but apparently had no symptoms other than the fever.

Six other members of the trip were confirmed to have the flu in subsequent tests.

The remaining members of the group were forced to remain in their Seoul hotel rooms until Thursday, while health officials made certain that they weren't also carriers of the flu.

The Straits Times in Singapore quoted South Korean health officials as saying that the students who were stopped in the airport with temperatures displayed symptoms before they got on the airplane for Seoul.

But Limtiaco said that all those with confirmed cases of swine flu — along with the other students on the trip — were asked by chaperones how they felt before boarding the plane for South Korea and all said they felt healthy.

She also has said all the students on the trip were required to get a health clearance before the trip. Those clearances were due June 12.

Chaperones were not required to get the health clearance. Limtiaco added that the chaperone with pneumonia "to our knowledge, did not have symptoms prior to departure."