Four Britons injured in a polar bear attack that killed one of their expedition's members are stable enough to return to Britain, Norwegian medical officials said on Saturday. The British Schools Exploring Society (BSES) meanwhile said the expedition had been cancelled and all other participants would be brought home following the death of 17-year-old Horatio Chapple. "The condition of the four is stable and satisfactory. They have all undergone stabilising surgery and will be able to leave Tromsoe," where they were flown for treatment after the attack, said Jan Mathisen, the head of emergency at the University Hospital of North Norway. The four had been treated for head injuries, he said. Two of the patients had moderate injuries and two were seriously hurt, he told reporters, according to Norwegian news agency NTB. In a statement, the hospital said the four, all males aged 16, 17, 27 and 29, could return to Britain at the earliest "late this afternoon or Sunday/Monday." BSES named them as team leaders Andy Ruck and Spike Reid, and students Scott Bennell-Smith and Patrick Flinders. It said the team, with 11 expedition members and two leaders, was one of seven "undertaking a long-term project to study glaciers and document changes since previous expeditions as part of ongoing scientific research into climate change." The 250-kilo (550-pound) polar bear attacked their camp site in the remote Svalbard archipelago early Friday, reportedly while they were still in their tents. Chapple, a student at Britain's prestigious Eton College, was mauled to death before the bear was shot and killed. The eight other campers were unhurt. Chapple's family said in a statement Saturday: "Horatio was so excited about his plans to be a doctor, strong, fearless and kind with an amazing sense of humour and an ability to laugh at himself. "He was on the cusp of adulthood and had a clear vision of where his life was going." Eton expressed its "deep sadness" at his death, saying, "Horatio was a very well-liked member of the school and respected by masters and boys alike. His loss is devastating to those who knew him." Britain's ambassador to Norway Jane Owen said the four injured had been treated well. "The only reason we want to send them to British hospitals is to be near their loved ones," she told NTB. "It has been difficult for the families to decide if they should come to Tromsoe or wait for them to come to Britain," she added. She told the BBC she had met the four injured in Tromsoe late Friday and that they were awake and could speak. "The investigation will be ongoing today and a lot of people will be looking into what exactly happened yesterday morning in what must have been a very frightening attack ... (by an) extremely large polar bear," she said. Owen added both the BSES and Norwegian authorities would be involved in the investigation. The group was attacked near the Von Post glacier in the Tempel Fjord, about 40 kilometres (25 miles) from the archipelago's capital Longyearbyen. Reports said the British campers had set up flares around their camp site to frighten the bears, but it is unclear if they worked. Local authorities interviewed the eight uninjured campers Saturday, a spokeswoman for the Svalbard governor told NTB. "Interviews are in progress," Liv Oedegaard said. "It's unclear who shot the polar bear, we will get the answer by investigating," she said. According to Norway's TV2, Friday's attack was the first deadly polar bear attack in Svalbard since 1995. Chapple's death brings to five the number of people killed on the archipelago since 1973, when polar bears became a protected species, it reported.