There had been indications that acts of sabotage could take place on the border with Kaliningrad in the coming days, police chief Marek Boron told the radio station RMF FM on Tuesday.
"We must ensure the safety of the citizens living there but also protect the infrastructure and deal with any possible situations that could pose a threat to the population," the police chief added.
Police in the border region have been reinforced with personnel from other parts of the country, he said.
The army's elite GROM unit is also deployed there, a military spokesman told the Fakt newspaper.
Poland, a member of the European Union and the NATO military alliance, shares a 232km-long border with Kaliningrad.
Polish Prime Minister Donald Tusk said Poland successfully prevented what appeared to be an attempted provocation on the border with Kaliningrad overnight.
He gave few details but said that "individuals with flashlights" had been observed in the border area.
The Polish guards prevented any incident from happening, he said.
Tusk said it was not possible to confirm with full certainty that the incident was an attempted provocation.
He said Russia's intensified escalation would continue and was unlikely to be limited to this incident.
The heavily fortified Russian territory is surrounded by NATO members Poland and Lithuania and is regarded as Russia's "unsinkable aircraft carrier".
Earlier this year there were reports in the US media citing new intelligence suggesting that Russian President Vladimir Putin might attempt to test NATO's resolve with a limited attack on a member state.
Possible scenarios range from a cyberattack to a small-scale incursion by soldiers in unmarked uniforms into a NATO country.
with AP
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