Hundreds of activists gathered on Wednesday outside the U.S. Immigration and Customs Enforcement building here to protest the arrests of more than 150 undocumented immigrants in recent days.

Local activist groups organized the “emergency rally” to respond to the mass arrests in Northern California, just two weeks after more than 200 people were arrested in similar raids in the Los Angeles area.

Some 200 protesters convened outside the ICE building in downtown San Francisco under an overcast sky, demanding an end to the raids. Several groups of demonstrators surrounded the building, shouting chants, marching, locking arms and carrying signs while police and ICE security looked on.

“We have come together today to show that the Northern California region stands together in denouncing the mass arrests that happened in the last three days,” Blanca Vazquez, a media spokesperson for the protest, told HuffPost.

Vazquez said activist groups had learned from ICE that an additional 10 or so arrests were conducted on Wednesday. ICE did not immediately respond to a request for comment.

At least half of those arrested as of Tuesday did not have criminal convictions other than their immigration violations, according to a statement from ICE. Those who did had convictions including “assault/battery, crimes against children, weapons charges and DUI,” ICE said.

In a statement on Wednesday, House Minority Leader Nancy Pelosi (D-Calif.) argued that the sweep “was intended solely to terrorize innocent immigrant families and instill fear in the hearts of our communities.”

The intended raids came to light on Saturday evening when Oakland Mayor Libby Schaaf told the local immigrant community she’d learned from “multiple credible sources” that, within the next 24 hours, ICE would be conducting operations in the Bay Area, including in Oakland.

Immigrant rights groups were on “high alert” following Schaaf’s announcement, Vazquez said.

In statement on Tuesday, ICE deputy Director Thomas Homan criticized Schaaf’s decision to warn immigrants of the raids, saying that “864 criminal aliens and public safety threats remain at large in the community… thanks to the mayor’s irresponsible decision.”

“The Oakland mayor’s decision to publicize her suspicions about ICE operations further increased that risk for my officers and alerted criminal aliens ― making clear that this reckless decision was based on her political agenda with the very federal laws that ICE is sworn to uphold,” Homan said.

Schaaf’s move also drew initial criticism from some activists who said her warning may have served to sow panic among immigrant communities. But the mayor stood by her decision, saying Tuesday that she feared the arrests would affect many undocumented immigrants who had no other criminal convictions ― which, indeed, turned out to be the case.

Oakland, San Francisco and many other cities and counties in California have declared themselves to be “sanctuary cities,” refusing to work with federal officials to detain and deport undocumented immigrants.