San Francisco officials this week moved to curb their partnership with U.S. immigration authorities, by ending a practice that facilitates deportations by extending the detention of illegal immigrants arrested for crimes.

The San Francisco Board of Supervisors action, which would exclude certain violent offenders, represents the latest pushback by state and local officials in California against the federal government over immigration enforcement.

The board voted unanimously to pass an ordinance to prevent the San Francisco police and sheriff’s departments from detaining illegal immigrants arrested for crimes for up to 48 hours past their release dates. The extra time helps immigration agents take custody of detainees for possible deportation.

The federal government, in 2008, launched the so-called Secure Communities partnership between U.S. Immigration and Customs Enforcement and local law enforcement to facilitate the deportation of illegal immigrants arrested for crimes.

It has drawn criticism from immigrant rights groups who say too many non-violent immigrants are being caught in the system, getting deported and being cut off from family.

The law is set to take effect 30 days from when San Francisco Mayor Ed Lee signs it, which could take up to 10 days. He cannot veto it because the board’s vote was unanimous.