The Scouts from all over the UK have joined over 3,000 others at the 20th World Scout Jamboree in Thailand.
They were due to split into groups to stay with families in Japan, South Korea, Taiwan, Singapore and Malaysia.
But now the 800 who were supposed to fly to the Philippine capital of Manila will have to go somewhere else because it's too dangerous.
The warnings that terror groups might target tourists over the New Year came from safety experts.
In the last two weeks alone, bombs have killed 30 people around the Philippines. Officials have blamed rebel Islamic groups.
And a bomb blast during the start of the country's New Year's Eve celebrations on Tuesday killed at least four people and wounded 26.
It's not clear who was to blame.
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