WARSAW 

As border controls were set up along Poland’s borders with Germany and Lithuania on Monday, Polish Prime Minister Donald Tusk told a press conference in Warsaw that “tough reactions will be used when necessary.”

During a meeting with Dutch Prime Minister Dick Schoof in the capital, Tusk said officers of the border guard and the police have a "clear order to react firmly" to any attempts to disrupt border controls.

Temporary border controls with Germany and Lithuania will be carried out randomly and be in force for 30 days, with the possibility of extensions.

Self-proclaimed “citizen patrols” on the German border have been set up to prevent the return to Poland of non-EU migrants who had previously entered Germany via Poland.

The government last week accused the patrols, which are backed by some right-wing politicians, of impeding the work of border officers and spreading misinformation about Poland being “flooded” with migrants.

Members of such groups have tried try check the ID of people crossing the border.

Tusk added that impersonating state services and obstructing activities will be severely punished. “We will apply adequate measures ... These will include fines, but if necessary, also direct coercion and detention,” he said, adding that that Poland would "effectively verify each case."

On the very first day of checks on the Polish-Lithuanian border, an Estonian citizen carrying four Afghan citizens in his car was detained.

Defense Minister Wladyslaw Kosiniak-Kamysz said Monday that the border control plan had been prepared before activists from right-wing circles appeared on the border.

“This is not under any pressure, it is for the purpose of protection. And the fact that extreme circles, activists ... want to disrupt the normal functioning of the services, often do not allow them to perform their duties, insult them – this is unacceptable,” he said.

The leader of Poland’s main opposition party, Law and Justice (PiS), Jaroslaw Kaczynski, on Sunday joined the Polish president in admonishing Berlin for exacerbating non-EU migrant flows into Poland and the Polish government for its “supine” response.

Polish Border Guards said last week that from Jan. 1 to June 29, over 4,600 illegal entries from Germany were recorded, most by citizens of Ukraine (40%), with others from Afghanistan, Somalia, Syria, Georgia, and Colombia.

According to Interior Ministry data, over 850 migrants who illegally entered Germany from Poland this year were people who came through Belarus.

The asylum claims of incoming non-EU migrants under the Dublin regulations need to be processed in the first country of entry in the EU.