Krîza Penaberan li Ewrupa - Îlon 16, 2015

Migrants react on the Serbian side of the border as Hungarian riot police fires tear gas and water cannon near Roszke, Sept.16, 2015. Police fired tear gas and water cannon at protesting migrants demanding they be allowed to enter from Serbia on Wednesday on the second day of a border crackdown.

A migrant throws a bottle toward Hungarian police at the "Horgos 2" border crossing into Hungary, near Horgos, Serbia.

Hungarian riot police, backed by water cannon and armored vehicles, moved into position at the border crossing with Serbia in Roszke where migrants are demanding they be allowed to cross from Serbia, a U.N. official at the scene told Reuters.

Migrants shout slogans as they stand in front of a barrier at the border with Hungary near the village of Horgos, Serbia, Sept. 16, 2015. Hungary's right-wing government shut the main land route for migrants into the European Union, taking matters into its own hands to halt Europe's influx of refugees.

Gorilla "Mjukuu" and her baby "Alika" check out a measuring device in an enclosure during a photocall at London Zoo to promote the zoo's annual weigh-in event.

Migrants hold a banner reading "Merkel" in front of a barrier at the border with Hungary near the village of Horgos, Serbia.

Gorilla "Mjukuu" and her baby "Alika" check out a measuring device in an enclosure during a photocall at London Zoo to promote the zoo's annual weigh-in event.

Migrants sleep in front of a barrier at the border with Hungary near the village of Horgos, Serbia.

Migrants make their way through fields at the border between Serbia and Croatia near Tovarnik, Croatia. The first groups of migrants have started arriving in Croatia - a new entry point into the European Union after Hungary sealed off its border with Serbia with massive coils of barbed wire.

Croatian police detain a group of migrants in Tovarnik after they crossed from neighboring Serbia.

Migrants walk towards Germany at the border crossing with Austria in Freilassing, Germany. Germany cut its train link with the Austrian city of Salzburg, shutting down the main route into its territory for tens of thousands of people caught in Europe's worst migration crisis in decades.

A street artist entertains in the compound outside the Berlin Office of Health and Social Affairs (LaGeSo) as they wait for their registration in Berlin, Germany.