The group was quarantined while on a study trip to Samoa after one of the students tested positive to swine flu.

Students and teachers flew home at different times last Thursday and Friday depending on when they had started courses of anti-viral drug Tamiflu. All returned to school yesterday.

Principal Carolyn Grantskalns said the trip to Samoa was part of a year 9 humanities subject that studies the culture and ideas of people and places, such as Vietnam and Samoa.

She said the school has taken students on several trips to Samoa.

"Their safety and wellbeing was always our first concern and that they had a very positive experience of Samoa despite the difficulties."

Only one student was diagnosed with swine flu and other girls who did not show signs of the virus were allowed to take part in activities related to the study trip.

Ms Grantskalns said the school communicated with parents of the children at least daily during the situation.

"It was a big group of girls and they had different amounts of time in quarantine.

"I think people [back home] were concerned but also aware that there were staff there taking very good care of the girls.

"For all the other girls the school has gone on [as per normal]."