Most of Tonga's schools have been closed for the day in response to a two hour tsunami alert following a 7.6 scale earthquake off the Kermadec Islands.
The Principal of Tonga College, Kalafitoni Latu, says his school is located on higher ground and he has kept students at the school for the morning waiting for roads to clear of traffic.
He says some parents collected their children and he sent all students home after congestion eased.
Mr Latu says the Minister of Education advised schools to temporarily close but some church-run schools have stayed open.
"All the government schools in the lower area are closed. I think the students are behave well because this is the fourth warning for us and they start to get used to this kind of emergency."
Mr Latu says he expects schools to re-open on Friday.