Moscow police have detained more than 400 migrant workers, mostly from former Soviet states, following a raid on a construction site in southeast Moscow.
In a statement on their official website, police described Wednesday's raid as a preventive measure to combat illegal immigration in the capital.
Immigration officials are now reviewing the identities and residency permits of the 411 people detained, as well as checking whether they have been involved in any criminal activity, the statement said.
Police discovered the migrants after searching a construction site shielded by a temporary metal fence on Privolnaya Ulitsa, 8 kilometers from the Moscow Ring Road. Those detained were mostly from Tajikistan, Uzbekistan and Moldova and had been living in sheds on the building site.
Police have opened roughly 250 misdemeanor cases against those detained for violating migration rules.