"A sanitary-epidemiological station, [used as] a mobile vaccination centre, was set on fire in Zamosc. A special operational investigative group will be created to investigate," the police said in a statement.
The incident took place on Monday morning, the police said, adding no casualties were reported.
Commenting on the incident, Prime Minister Mateusz Morawiecki vowed to introduce a harsh punishment for similar actions, noting that vaccinations will shield the country from a fourth wave of the coronavirus.
Poland is currently witnessing a rise in COVID-19 infections, with over 2.8 million infections confirmed since the onset of the pandemic.