PORTLAND – Maine law enforcement officers say bills under consideration in Congress that seek to increase state and local enforcement of immigration laws could actually hurt their ability to protect public safety.

“They should supply federal agencies with the resources and manpower and not reach into the local communities to subvert the relationships we’re trying to promote with new arrivals,” Portland Police Chief Michael Chitwood said.

But supporters of tougher immigration enforcement say the only way to make a dent in illegal immigration and corral foreign terrorists is for local and state police to start checking whether people are here legally.

A bill proposed in the U.S. House would require states to authorize police to investigate and apprehend people in the country illegally. A corresponding bill in the Senate so far has not gained as much support as the House measure.

The bills target communities like Portland, which last year passed an ordinance forbidding police officers from checking people’s immigration status unless they suspect the person of committing a serious crime or being a threat to national security.

Having local police enforce immigration law runs counter to the concept of community policing, Cumberland County Sheriff Mark Dion said.

“Local law enforcement can’t work unless people trust us enough to talk to us,” he said. “The mission of public safety is safety first, and law enforcement follows from that.”

Police said they were wary of taking on responsibilities better left to federal officials who can specialize in immigration law.

“It is far more important in my view that our roads are kept safe, people’s rights are upheld and their homes and families are also protected,” Maine Public Safety Commissioner Michael Cantara said.

David Ray, associate director of the Federation for American Immigration Reform, said it takes almost no time for officers to check a person’s immigration status in the course of normal police work, and it could save lives.