A search through the night has failed to find five French tourists who fell through ice on snowmobiles while on an excursion in northern Quebec, Canadian police said Thursday. Two snowmobiles similar to those used by the original group of eight tourists and their Canadian guide were found Wednesday at the bottom of Saint-Jean Lake near where the accident occurred. A search on land for the missing tourists was pressed through the night Wednesday and early Thursday but turned up nothing, a spokesman for Quebec provincial police told AFP. A third team of divers and a helicopter were joining the search at sunrise, he said. The area is about 225 kilometers (140 miles) north of Quebec City. Investigators are still hopeful the French tourists managed to find refuge on an island or a chalet but have been unable to communicate. "But the more time passes, the less likely this becomes," he said. The snowmobiles crashed through ice Tuesday evening at a dangerous spot where Saint-Jean Lake funnels into a river. The area is off limits to snowmobiles because the ice is thinner there. Police said they were alerted by two of the tourists who had rescued a third from the water. The 42-year-old guide, Benoit L'Esperance of Montreal, was pulled out by emergency response teams and taken to hospital, but he died overnight. The surviving tourists were briefly hospitalized and treated for exposure and shock. Investigators do not know why the group left the approved paths to venture "off-piste" at nightfall, but some experts believe they may have been trying to take a short-cut to their destination. et/leo/jm/ch