Polish President Andrzej Duda has imposed a state of emergency in parts of two regions bordering Belarus amid an influx of migrants from the former Soviet state.
The September 2 decision came following a request by his government earlier in the week.
The emergency rules would ban demonstrations in a thin strip along the border as well as require people to carry identity documentation.
It will last for 30 days but could be extended by Duda.
About 3,000 migrants tried to enter Poland last month from Belarus.
Poland and the EU believe the illegal crossings are being orchestrated by strongman Alyaksandr Lukashenka to extract revenge for sanctions against his authoritarian rule.
The EU has imposed several rounds of economic penalties against members of Lukashenka’s government, state-owned companies, as well as tycoons that have benefitted from his rule following his brutal crackdown on protesters.
Migrants from Belarus have also entered Latvia and Lithuania, two other EU member states that border the country. Most of the migrants are from the Middle East, including Iraq and Afghanistan.
Poland last week began the construction of a 2.5-meter-tall fence along its 418-kilometer border with Belarus to slow the inflow.
The state of emergency is the first in Poland’s postcommunist history.