PEOPLE have always slipped back and forth across Canada’s 5,525-mile (8,892-km) border with the United States, which runs through forests, mountains, farm fields and the Great Lakes. But a sharp increase in the number of refugees illegally coming north across the border has alarmed Canadians. Anecdotal evidence suggests the numbers are still small: they are coming in hundreds, not thousands. But the trend—a doubling or tripling of illegal crossings near some border posts in the past year, and tales of refugees losing fingers to frostbite—has captured public attention in Canada and put pressure on politicians to respond. Why are refugees heading north?

The current crop of refugees, mostly from the Middle East and Africa, are attracting special attention because their flight follows the election of Donald Trump as president and his controversial executive order on immigration. Those questioned by a representative of the UN High Commissioner of Refugees said they no longer feel safe in the United States, because of a rise in anti-immigrant rhetoric, and fear that their asylum requests will not be dealt with fairly. If they presented themselves at an official border post most would be turned back under the Safe Third Country Agreement between Canada and America. So they cross snowy fields in northern Minnesota or scramble over ditches in upstate New York instead. Once they set foot on Canadian soil they can apply for asylum. The government has not released comprehensive figures. But the Royal Canadian Mounted Police, the national force with jurisdiction between border posts, says it intercepted 1,280 refugees between April 2016 and January 2017 at the most popular illegal-crossing point in Quebec. That is triple the number of the previous year.

All of this is music to the ears of liberal Canadians and plays to the Liberal government’s positioning of Canada as an open country with a prime minister, Justin Trudeau, who hugs refugees. After Mr Trump signed his first executive order on immigration from seven Muslim-majority countries, Mr Trudeau tweeted, “To those fleeing persecution, terror & war, Canadians will welcome you, regardless of your faith.” Not all Canadians agreed. The majority support immigration. A whopping 82% told a polling agency in 2015 that immigration had positive economic benefits. Yet they are sceptical of refugees. Almost 50% in the same poll said they believed most people claiming to be refugees are not credible. There are mutterings about queue-jumpers and security threats. It could become a clamour if the government is not seen to be in control.

The Conservatives, who form the official opposition in parliament, see the refugee infiltration as a security risk and want the government to devote more money and resources to policing the border. The left-leaning New Democrats want Canada to suspend the Safe Third Country Agreement on grounds that America is no longer safe for refugees. That is unlikely to happen. The UN refugee agency, which monitors the agreement, says actions taken in the United States have not undermined its asylum system. Refugees are being driven by fear rather than fact. Ralph Goodale, the minister of public safety, has called for calm while he mulls his options and consults with Americans. He has limited time to act. Officials predict illegal crossings will surge once warmer weather arrives. Mr Goodale may be the only Canadian not longing for spring.