World

Austria checking trucks for migrants, creates huge traffic jam on main Budapest-Vienna highway

  • Refugees from the Middle East are silhouetted against the setting sun as they walk on railway tracks from Serbia, in Roszke, Hungary, Sunday, Aug. 30, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)

    Refugees from the Middle East are silhouetted against the setting sun as they walk on railway tracks from Serbia, in Roszke, Hungary, Sunday, Aug. 30, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)  (The Associated Press)

  • Refugees who crossed the border from Serbia climb on a road to board a bus to transfer them to a refugee camp, in Asotthalom, Hungary, Monday, Aug. 31, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)

    Refugees who crossed the border from Serbia climb on a road to board a bus to transfer them to a refugee camp, in Asotthalom, Hungary, Monday, Aug. 31, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)  (The Associated Press)

  • A Hungarian policeman observes terrain at the border with Serbia, looking for refugees crossing the barbed wire fence, in Roszke, Hungary, Monday, Aug. 31, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)

    A Hungarian policeman observes terrain at the border with Serbia, looking for refugees crossing the barbed wire fence, in Roszke, Hungary, Monday, Aug. 31, 2015. Migrants fearful of death at sea in overcrowded and flimsy boats have increasingly turned to using a land route to Europe through the Western Balkans. (AP Photo/Darko Bandic)  (The Associated Press)

Austria's decision to start inspecting trucks at its border with Hungary after 71 migrants died in a food truck has created a huge, 25-kilometer (15 1/2-mile) traffic jam on the main Budapest-Vienna highway.

The Hungarian traffic firm Utinform reported the backup at the Hegyeshalom border crossing Monday and said traffic was slower than usual at other Hungary-Austria border crossings.

Both countries are part of the European Union's Schengen zone of passport-free travel. Under normal circumstances, vehicles are rarely inspected at the border anymore.

Austrian police say the 71 migrants likely suffocated to death in a truck with Hungarian license plates abandoned last week in Austria on the Budapest-Vienna highway. Five suspected human traffickers have been detained in the case and Hungary is stepping up its arrests of smugglers.