The women still have their passports and wallets, which they carried in their day bags, but the theft was still a shock.
They are in the final days of a 10-week trip around New Zealand including five weeks as conservation volunteers in Auckland and the West Coast.
They planted trees, got rid of weeds and helped build bike tracks.
Ms Brueckner said the break-in was upsetting but said it would not ruin their trip.
"There are thieves all over the world, and a lot of people have also been supporting us."
The two had planned to travel to Cape Reinga yesterday but were instead taken in for the night by a Kerikeri couple.
Others donated replacement bags and clothing.
They expected to resume their travels today and leave New Zealand on June 1.
It was not clear how the thieves had entered the locked campervan. In the case of the college van they had smashed a rear window and made off with six bags.
Seven Year 13 history students were on a field trip researching pre-1840 interactions between missionaries and Maori.
A few lost wallets with cash, bank cards and driver's licences, but most lost only packed lunches and homework.
Teacher Alistair Leitch said it was sad that someone would stoop to stealing school bags from a clearly marked school van.
"Some of the students are pretty upset. You just feel violated," he said.
Sergeant Phil Le Comte, of Kerikeri, sad police wanted to speak to a couple seen in the carpark in a silver-grey car.
The driver was a female Maori aged about 20-30 with dark hair pulled back from her face. Her passenger was described as a male Maori aged about 30 with unkempt hair and facial hair or stubble. He was wearing a sleeveless green polarfleece top with a yellow high-visibility neckline.
Mr Le Comte urged the couple, or anyone who knew who the two were, to contact him at the Kerikeri station on (09) 407 9211. Anonymous tips can be made to Crimestoppers on 0800 555 111.
