Federal immigration authorities attempted raids in at least two neighborhoods in New York City on Saturday, according to a person familiar with the matter, a day prior to when President Trump had said Immigration and Customs Enforcement agents would begin national roundups of people illegally in the U.S.

In New York City, ICE agents went to residences in the Harlem section of Manhattan and Brooklyn’s Sunset Park neighborhood, the person said. The agents were rejected by people at the residences because they didn’t have warrants, but plan to return at least to Sunset Park tomorrow, according to the person…

The raids are set to begin in 10 cities—many which have designated themselves as sanctuaries for undocumented immigrants—Miami, Atlanta, Chicago, Baltimore, Denver, Houston, Los Angeles, New Orleans, New York and San Francisco, said officials of the Refugee and Immigrant Center for Education and Legal Services, a Texas-based nonprofit. Protests were held in many of the cities Friday and Saturday.

Immigrant-rights advocates vowed to protect undocumented residents they say are being victimized by the Trump administration for political reasons. Many of the immigrants, they say, fled violence in countries such as Guatemala, Honduras and El Salvador and face possible harm if they are sent back.