Schools are reconsidering their overseas programmes after the bird flu outbreak in China, and the possible threat of conflict in the Korean peninsula.
Tour agencies that The Straits Times spoke to last week said the schools that had planned to go to South Korea or China in the next few months have approached them with concerns.
Some have just inquired about the situations over there, but others are looking at alternative destinations. They are also thinking about deferring the trips, hoping that the situations in both countries will improve with time.
Tensions have increased in the Korean peninsula after provocative moves from North Korea, including making threats of war.
International Paradise Connexions Travel, which says it handles between 800 and 1,000 school groups in a year, told The Straits Times that five schools that had planned to go to South Korea are thinking of going elsewhere.
In the case of China, it said, five to six schools, out of 30 groups, have voiced concerns over the H7N9 bird flu outbreak, which has claimed at least nine lives in East China.
Other tour agencies that work with schools have reported scheduled trips being postponed.
Chan Brothers Travel told The Straits Times that of the schools that asked for quotations for trips to both countries, three preferred to defer the tours.
One school that has confirmed a Chan Brothers tour package to South Korea in June also postponed its trip to September.
Golden Travel Services has also seen schools that booked learning trips to Shanghai move them to September.
The Ministry of Education (MOE) said that it is monitoring the situation and will take appropriate measures if necessary.
Schools also told The Straits Times that the safety of students is paramount.
"Should the situations change unfavourably, we will act accordingly and appropriately, with our staff and students' safety in mind," said Ms Karen Lim, corporate communications manager at Raffles Girls' School, which is conducting trips to South Korea and China this year.
However, some schools were less willing to go ahead with their trips. In response to parents' concerns, River Valley High School has taken precautions by calling off trips to South Korea and areas in China with reported cases of the H7N9 bird flu. The school does not intend to replace these with other trips.
Students from Anglo-Chinese School (Independent) whom The Straits Times spoke to also said their school is considering alternative destinations for their community service trips to China next month, or postponing them.
"I guess I'm worried," said Kevin Wong, a 17-year old student from ACS(I) who is supposed to go to Kunming, China, with his class next month.
"But I feel quite safe because I believe that if it is dangerous, the MOH (Ministry of Health) will stop me."
The school has said that it is getting feedback from its local contacts on the situation, and will keep parents and students updated.