About 2,000 gathered in Stockholm for a protest Saturday, and 1,000 marched from Mollevangstroget to Davidshallstorg, The Local.se reported.
Demonstrators were protesting against police methods for searching for undocumented migrants, as many have criticized police for singling out foreign-looking people during subway checks.
Swedish police are not allowed to stop and search people based on their looks, names, or the language they speak, The Local.se reported.
Instead, police have stopped passengers on the suspicion of ticket violations, and then checked their IDs, The Local.se said.
Police have denied that they are singling out foreign-looking people, but announced Friday that they would no longer run ID checks on subways as part of the search for illegal immigrants.