Authorities sent helicopter deliveries of food and medicine to iced-in Bosnian villagers on Wednesday as Europe\'s 12-day-old killer cold snap tightened its frigid grip on the continent. Heavy snows eased in Bosnia but the bitter cold continued, especially in the south and southeast, where temperatures dropped to minus 20 degrees Celsius (minus 4 Fahrenheit.) Thousands struggled without power, including in the region around the historic city of Mostar, famed for its 16th Century Ottoman bridge, where some 15,000 homes were without electricity. Europe\'s big chill has so far claimed more than 400 lives, especially in eastern countries such as Poland and Ukraine, which between them have tallied more than 200 fatalities, and dozens more have died from the weather\'s secondary effects, such as being asphyxiated by shoddy heating. Uma Sinanovic, a spokeswoman for Bosnia\'s defence ministry, said areas around Nevesinje and Berkovici in the country\'s south were especially hard hit. \"The electricity has been down for two days, phone lines are also down in that region,\" Dragan Stark of the Bosnian Serb civil protection service added. \"It\'s a disaster.\" As they have previously done in other areas, Bosnian authorities on Wednesday sent civilian and military helicopters to isolated hamlets near Mostar and Kalinovic, bringing much-needed supplies and ferrying sick people to hospitals. Five military and civilian choppers delivered basic food stuffs like flour and oil, hoisting the supplies down by rope when landings were impossible. The Bosnian authorities said Wednesday that a seventh person had died from the cold in the rugged mountainous Balkan nation. Russian authorities announced at least 110 people had died as a result of the cold so far this year, with 44 of them killed in February alone. \"Weather like this is only once in five years, it\'s usually much warmer,\" Moscow resident Pavel Sterlikov said. Elsewhere, ice clogged parts of the Danube, one of Europe\'s main arterial waterways, with a 180-kilometre (111-mile) stretch frozen between Croatian border and the Belgrade suburb of Banovci, and similar-sized stretch blocked between Kostolac to a hydropower plant on the Romania border. An icebreaker left the port of Prahovo in the east to try to keep the river from freezing over entirely, the director of Serbia\'s top water body Nikola Marjanovic said. About 40 Serbian villages have declared a state of emergency as 70,000 people remained cut off from the outside world. Croatian villagers have experienced some of the toughest conditions in the Balkans, especially in the southern region where more than 100 villages were still cut off for the sixth consecutive day. Miserable conditions persisted in Bulgaria, with violent snowstorms raging in the Danube plain in the northeast, where all traffic has been suspended since Tuesday and where the main border crossing between Bulgaria and Romania was closed due to ice. At least eight drowned Monday after a burst dam sent freezing waters into the village of Biser. Authorities continued to search for two missing residents and Bulgaria announced a national day of mourning. Officials warned that heavy snow storms could trigger floods when the spring melt begins, and the government was implementing urgent measures to strengthen dams and riverbeds. Ukraine remained the worst-affected country, with hundreds of cars stranded on the Crimean peninsula and at least 131 deaths so far attributed to the cold, while three more people froze to death in Romania, bringing that country\'s total to 41. The Hungarian Central Bank, meanwhile, said it literally had money to burn to help the country\'s homeless. The bank has been pulping wads of its retired forint banknotes and turning them into briquettes, which make useful heating fuel. Famished wolves scavenged in the isolated, snow-covered Italian village of Trasacco, while keepers at the Berlin zoo imposed a cold-related curfew on the giraffes and antelopes, which will be kept inside for all but 2.5 hours each day. While conditions have been brutal for much of Europe, residents in the Netherlands were waiting with bated breath to see if the country\'s canals would freeze hard enough to allow a legendary ice-skating race to take place. For the so-called Elfstedentocht (11 city) race to take place for the first time in 15 years, the ice needs to be at least 15-centimetres (six inches) thick along the entire 200-kilometre (124-mile) route, but ice cover remains patchy along some stretches. French power suppliers saw an all-time record for electricity demand Tuesday night and Paris got a dusting of snow. France has so far counted five cold-related deaths. Forecasters expect the cold to last until at least next week.