The German federal government reintroduced border controls Sunday to slow the influx of immigrants arriving from Hungary via Austria, temporarily overriding the stipulations of the Schengen Agreement, which abolished internal borders and passport controls for the 26 participating states.

Until further notice entering Germany will require valid travel documents.

Following Germany’s example, the Czech Republic announced similar measures for its border with Austria. Czech interior minister Milan Chovanec said Sunday evening that the border with Austria would be secured, and that further action could be taken depending on the development of the situation.

Already by 7:00am on Monday Bavarian authorities reported 2-4 mile backups at the crossing points of major highways leading into Germany near the Austrian city of Salzburg and at Germany’s Passau border.

Germany resumed train services from Austria into Bavaria at 6:00am Monday morning after having suspended them on Sunday.

On Sunday evening, German Interior Minister Thomas de Maizière held a press conference in Berlin to formally announce the decision, and declared that the measure was taken for security reasons. “We need more time and a degree of order on our borders,” he said.

Bavarian Interior Minister Joachim Herrmann said he expects that the reintroduction of border controls will last at least several weeks, noting that many trying to make the crossing “are not real refugees.”

No sooner had border checks at the German-Austrian border begun, in fact, than the police arrested an Italian man allegedly attempting to smuggle eight Syrian refugees across the border in a van.

By Monday morning the number of arrests had grown to over 30 traffickers just at the Austrian border with Passau. In addition, more than 100 refugees have been taken in, according to local government spokesman, Thomas Schweikl.

The decision came in the midst of some dramatic events at Munich train station this weekend, as well as a growing reaction within Germany opposing Angela Merkel’s decision last week to allow unregistered refugees to enter the country.

On Saturday, over 13,000 refugees arrived at the station on trains from Austria, with another 1,400 arriving on Sunday morning. The mayor, Dieter Rieter, said Munich was “full,” and that its capacities were completely overwhelmed. Some migrants slept Saturday night on the station concourse.

De Maizière’s claim that the new measures are in accordance with the provisions of the Schengen Borders Code was echoed by a statement by the European Commission Sunday night. The Commission confirmed that on preliminary examination the reintroduction of border controls by Germany was lawful, since the Schengen Agreement expressly provides for exceptional procedures for crisis situations.

This is not the first time the Schengen Agreement has been temporarily suspended in Germany, with controls reinstated most recently for the G-7 Summit held in the Bavarian Elmau Castle last June.

The federal government has said it needs time to cope logistically with the large crowds of migrants. Bavaria has been particularly affected by the onslaught, but so has the North Rhine-Westphalia region, where tens of thousands of migrants have transferred in recent weeks. Germany also wishes to send a signal to possible refugees, that entry into the country is not a given.

Der Spiegel reported that the German government is considering using German soldiers as well for border security, backing up the federal police.

Last month de Maizière had warned he could not rule out a suspension of the Schengen agreement, adding that it was time other European countries took greater responsibility for the migrant crisis, especially Great Britain.

While Greece and Italy have been the first port of entry for the majority of immigrants and refugees, Germany has continued to carry the brunt of those seeking permanent residence. This year alone Germany expects up to 800,000 people to seek asylum, far more than in any other EU nation.

Last week Germany’s foreign minister Frank-Walter Steinmeier warned that the influx of hundreds of thousands of migrants could be “the biggest challenge for the EU in its history.”

“If we are united in describing the situation as such, we should be united that such a challenge is not manageable for a single country,” he said.

Follow Thomas D. Williams on Twitter @tdwilliamsrome