Law / Stopped by the Poland's Police for no reason while walking at night [94]

So me and my friend were walking at night last Thursday near from his apartment and suddenly the police car stopped and one of the officer came to us asking for IDs I asked him why he didn't responed and kept asking for the IDs we gave him ours went to the car and registered our information and asked where we live and what are we doing in poland

We told him we are students and etc I asked him why are you taking our info he said it's a dangerous place keep away from it , I know it's not because my friend lives there and it's near college of medicine in krakow , also I think it's not a good reason to stop us is it a lawful act for police to stop people in the street and take there info ?

Ps ( we have brown skin )