COPENHAGEN/STOCKHOLM - Denmark imposed temporary identity checks on its border with Germany on Monday following a similar move by Sweden, dealing a double blow to Europe's fraying passport-free Schengen area amid a record influx of migrants.Sweden began checking documents of travelers from Denmark on Monday for the first time in half a century, causing delays of up to 50 minutes for trains and buses crossing the 4.9 mile (7.9 km) Oresund Bridge, Europe's longest combined road and rail bridge. However private vehicles were exempt from the checks.Denmark's prime minister said Sweden's move gave his country no option but to impose its own border controls and he appealed to the European Union to take "collective decisions" to better protect its external borders against the tide of migrants."The Swedish ID checks can increase the risk of a large number of illegal immigrants to accumulate in and around Copenhagen," Lars Lokke Rasmussen told a news conference in Copenhagen, justifying the new controls on the German border.Last year some 163,000 refugees sought asylum in Sweden, the largest number for any EU country relative to its population. But with arrivals running at around 10,000 a week in November, mostly traveling through Denmark, the Swedish government has said it is time to tighten border controls and asylum rules."A dark day for our Nordic region," former center-right Swedish foreign minister Carl Bildt said on his Twitter feed on Monday to describe the imposition of border checks.Thousands of commuters daily use the Oresund Bridge - familiar to fans of the 'Nordic noir' crime drama series "The Bridge" - to shuttle by car, train and bus between the Danish capital Copenhagen and the Swedish city of Malmo.Travelers expressed dismay at the new checks."I paid 230 euros for these tickets. This is Europe, not Africa. Why these checks?" said Gezahegn Abebe, an Ethiopian migrant living in Norway as he stood in the train station by Copenhagen airport before trying to head to Sweden.Returning home from a visit to Germany, Abebe said he had not been allowed through by security guards when he showed his Norwegian residence permit. Unlike Sweden and Denmark, Norway is not in the EU but it is a member of the Schengen zone."They said this is not a passport. If you don't have a passport you can't go," Abebe said.