A Bangkok international school cancelled classes for hundreds of students this week in the second wave of the type A (H1N1) influenza outbreak in Thailand.

The British school, Bangkok Patana School (BPS), posted letters dated Wednesday on its website informing parents about the closure of Year 6 and Year 8 classes after some students who returned from aboard were confirmed as having the H1N1 flu. They told those students to remain at home at least until Monday.

A parent told The Nation yesterday that around 300 students would be missing classes. Students from the two grades were contacted by their class and subject teachers by e-mail, by the homework database or through the eClassroom outline of assignments, according to the website www.patana.ac.th.

The messages say the BPS has also been taking advice from the relevant public health authorities, including the Bangkok Metropolitan Administration (BMA).

The BMA suggested closing the two grade groups.

"We have requested all children with influenza-type symptoms be kept at home and medically checked until such time as they have been certified fit to return to school. We have also been maintaining our high-level cleaning regime of the school buildings," letters signed by the head of school Matt Mills, principal of BPS's secondary school Mick Smith and principal of BPS's primary school David Knott say.

BMA deputy governor Dr Malinee Sukavejworakit, in charge of public health, told The Nation yesterday the school reported that it discovered one of its students had the flu on October 29 and on November 2 - Monday - three others also showed flu symptoms after their overseas trips.

"The BMA immediately responded to the report by assigning doctors and nurses to meet with the sick students. Currently, no more schools have reported the infection," Malinee said.

She added that the BMA educated the school on how to clean the influenza virus at the school's buildings to ensure the outbreak would not spread further. She said students with flu symptoms should be isolated from other students.

"Our sanitation officials will keep an eye on the outbreak at the school until it is back to normal," Malinee said.

The BMA will today kick off a flu campaign at a school in Bangkok's Lak Si district.

The campaign will encourage responses and collaboration from people in different careers - such as factory workers, civil servants and grocery-shop owners - to help them handle the second wave of the flu outbreak, Malinee said.