Kiwi students on a Central America field trip have been left shaken after being robbed by armed bandits.

Raiders reportedly wielding guns, knives and machetes made students from Christchurch's Burnside High School hand over their bags and money in the terrifying night attack in Costa Rica two days ago.

The Herald understands that 15 Burnside Year 12 pupils are on the trip run by travel firm Antipodeans.

Two teachers are with the group, along with an Antipodeans leader.

Today, Burnside High School associate principal Andrea Griffin confirmed the shocking ordeal.

She said although nobody was physically hurt, the group has been left "very shaken" by the December 10 campsite attack.

"The group was confronted by armed local men. Bags and valuables were taken, although all passports were later recovered," she said.

"Local police and Red Cross supported the group initially and they were transferred to a safe compound. They continue to be supported by Antipodeans, who are sending additional staff to support them.

"As a school we are saddened by this event and are doing everything to support the teachers, students and their families."

The children arrived in Costa Rica on December 4 for the month-long adventure and were four days into a mountain trek when the attack happened.

The armed men were "threatening", a source said, and demanded the kids' bags and money.

However, they managed to keep hold of their passports, which they had strapped on their person, as they had been advised to do.

"They're all safe … Luckily nobody was hurt," said one parent, who did not wish to be named.

"They were effectively attacked in tents at night on a mountainside."

The group has since been escorted off the mountain and taken to the coast where they were heading next.

Antipodean Adventures, an Australian and New Zealand company, has been approached for comment.

It's understood they have sent company representatives over to Costa Rica to assist.

Discussions on ongoing over whether the school group will continue with its itinerary or return to New Zealand.

Antipodean Adventures, which has offices in Auckland, Sydney and Melbourne, offers high school students three-to-four-week expeditions around the world, including Cambodia, Galapagos, India, Sir Lanka, Tanzania, Thailand, Timor-Leste and Nicaragua.

Pupils participate in community service projects while abroad as well as exploring and sightseeing.

The Costa Rica package takes in the legendary forests of Monteverde and swimming and snorkelling off the beaches of the Caribbean or Pacific coasts.

Its website says it has had "no major incidents" in 28 years and provides "24/7 support at home and overseas".

"The preparation we go through for every trip is unprecedented in the industry, meaning students, teachers and leaders are better prepared and more confident on trips," Antipodean Adventures says.

Burnside High School, with a roll of 2526 students, is the largest secondary school outside of Auckland.

Notable alumni include former Prime Minister John Key, Man Booker Prize winner Eleanor Catton, and Opera pop singer Hayley Westenra.