WASHINGTON >> Attorney General Jeff Sessions took new steps today to punish cities he believes are not cooperating with federal immigration agents in a move that was met with bewilderment by local officials who said they did not know why they were being singled out.

The Justice Department sent letters to four cities struggling with gun violence, telling them they would not be eligible for a program that provides money to combat drug trafficking and gang crime unless they give federal immigration authorities access to jails and notify agents before releasing inmates wanted on immigration violations.

Baltimore, Albuquerque, and Stockton and San Bernardino in California all expressed interest in the Justice Department’s Public Safety Partnership, which enlists federal agents, analysts and technology to help communities find solutions to crime.

“By taking simple, commonsense considerations into account, we are encouraging every jurisdiction in this country to cooperate with federal law enforcement,” Sessions said in a statement that accompanied the letters. “That will ultimately make all of us safer — especially law enforcement on our streets.”

The threat marks Sessions’ latest effort to force local authorities to help federal agents detain and deport people living in the country illegally as part of a push to reduce crime he believes is linked to illegal immigration. The attorney general has repeatedly vowed to withhold federal money from cities that do not cooperate, similar to how previous administrations have held back highway funds during debates over the speed limit and drinking age.

But it was not immediately clear to some of the cities why they were targeted.

The Republican mayor of Albuquerque previously declared that his city is not a sanctuary for immigrants without legal status. Peter Simonson, executive director of the American Civil Liberties Union in New Mexico, called the demands “a bullying tactic.”

Another concern raised by cities is that police who patrol the streets book suspects into jails run by county or state authorities over which they have no control. The Justice Department’s letters focus on giving federal immigration agents access to such detention facilities.

In San Bernardino, officers book anyone they arrest into jails that are run by the county, not the Southern California city of 216,000 people, said Police Chief Jarrod Burguan.

“The city of San Bernardino has never taken any formal act to declare itself a sanctuary city,” Burguan said. “Our policies have been very, very consistent over the years.”

In Baltimore, police do not enforce immigration laws, and arrestees are taken to a jail run by the state, said Anthony McCarthy, a spokesman for Mayor Catherine Pugh. The state says it adheres to federal policies on immigration in its detention system.

“We are receiving tremendous federal support for the violence-reduction actions, and we wouldn’t want anything to deter the progress we hope to make on that front,” McCarthy said.

Sessions has pledged to make fighting immigration and street crime the Justice Department’s top priority, but the strategy is putting him at odds with some city leaders, who say the best way to fight crime and build community trust is to keep local police out of federal immigration matters.

Last week, Sessions told cities they must meet the same conditions or lose out on millions of dollars from a separate grant program that helps police departments pay for everything from bulletproof vests to body cameras, a move that made some local officials more defiant.

In the four letters, the Justice Department asked the prospective cities’ police departments to show proof of their compliance by Aug. 18.

In Albuquerque, immigrant student activists said the letter was part of the Trump administration’s broader attack on immigrants.

“It is a vision of terror for families like mine,” said Gabriela Hernandez, Southwest Organizer for United We Dream.

The Justice Department in June tapped 12 cities to receive aid through the Public Safety Partnership, and officials said the four cities that had expressed interest in the next chance at participating. Cities were chosen based on higher-than-average rates of violence and willingness to receive the help and training.

Cities that want to be involved going forward will have to show they allow unfettered communication between police and federal immigration authorities, give agents access to jails in order to question immigrants, and provide them with 48-hour notice when someone in the country illegally is about to be released.