Gunmen forced a group of 16 British students and staff from their vehicle during a roadside ambush on an expedition in Africa.
Money, cameras and mobile phones were stolen as the robbers rifled through their belongings during the hold-up in the Tabora region of Tanzania.
The group of 14 students, aged 15 to 18, and two staff from private Cranbrook School in Kent were "shaken" but uninjured following the robbery last month.
A police escort was assigned to them for the remainder of the four-week trip by the regional police commissioner, headmaster John Weeds said.
Mr Weeds said: "The vehicle was not targeted, and there were a number of other local people in the same queue of traffic involved. It wasn't just about the students. The students were fine. There is no accounting for the emotional effect of such an episode as that is difficult to diagnose, but they came back in high spirits.
"We will review what happened but we are very enthusiastic about sending our students to the developing world. It's a very valuable way of broadening horizons. It gives some experience of a completely different environment in a controlled way."
The school has been sending students to east Africa for around 30 years to work alongside local people on aid-related projects and to learn about their culture.
Mr Weeds praised the response of the Tanzanian police to the robbery, and parents of the students involved in the ambush were informed.
Four men are due in court after admitting robbery, according to reports. Mr Weeds said: "We understand that the police have got to the bottom of who was responsible."